US2254700A - Heat treating apparatus - Google Patents

Description

P 1941- H. w. JONES 2,254,700

HEAT TREATING APPARATUS Filed May 1, 1940 I I 'll BY i ATUDRNEY Patented Sept. 2, 1941 HEAT TREATING APPARATUS Homer W. Jones, Westiield, N. J., sssignor to The Linde Air Products Company, a corporation of Ohio Application Mayl, 1940, Serial No. 832,648

13 Claims.

This invention relates to the heat treatment of-metal bodies having a plurality of integral the laterally extending portion of each cam may be registered in operative relationwithrespect portions of the same longitudinal extent, or a plurality of laterally extending portions, and

-more particularly to the heat treatment of cams upon a camshaft. This'invention also relates to apparatus for hardening in succession selected surface portions of a plurality of camsupon a camshaft, in which the surface portions to be hardened are heated by a source of localized high temperature heat, such as an oxyacetylene blowpipe flame.

Cams are generally used" to lift or actuate cam followers, and each cam upon a camshaft is usually adapted to actuate a follower only once during each rotation of the camshaft. Conse-- quently,'the greater part of the surface of each cam normally is cylindrical and a laterally extending portion, usually substantially triangular in cross-section, is disposed at the point at'which to a single blowpipe head; and, generally, to provide such apparatus which willbe simplein construction and economical in operation.

Other objects and novel features of this in:

, vention will'become apparent from the followmg description and accompanying drawing, in

which:

Fig. 1 is a side elevation, partially in section,

'of apparatus, constructed in accordance with this invention, for hardening in succession a plurality of cams upon a camshaft;

Fig. 2 is a horizontal sectional view of the apparatus ofl, looking downwardly along line 2-2 of'Fig. 1; and

the cam follower is lifted or actuated. Since the greatest wear will occur on this laterally extending portion, which also may be termed the apex, it is usually necessary to harden only the surface of the apex. Of course, when desired, a greater portion of the surface of each cam may be hardened.

The various physical dimensions of camshafts, such as overall length, distancebetween cams, cam widths, and cam ramp contours, tend to vary widely. Consequently, apparatus for successfully hardening at least the laterally extending portions or apices of cams must necessarily beso coristmcted that the least possible time will be required to align a laterally extend ing portion'of a cam being treated with the heatsuccession the apex of each cam; a registering Fig. 3 is a fragmentary vertical view, illus-' trating the attachment of motor-operated means for reciprocating the blowpipe of the apparatus of Fig. 1'.

In accordance with this invention, apparatus A for hardening in succession selected surface portions of a plurality of cams -on a camshaft may comprise, in general, a support S for a camshaft A having cams C; a blowpipe B for heating in device R for aligningcams andplacing them in properposition for heating; and a tank '1', containing quenching fluid Q. As soon as the surface of the apex of a' camhas been heated, the

blowpipe B may be withdrawn ina'horizontal direction, the heating gases automatically turned off by a valve V-which controls the flow of heatin 'downwardlybya handwheel H, the cam and its gases to blowpipe B, and support S moved heated apex thus beinglowered into quenching ing' means, or to make adjustments for cam spacing and other variables.

The objects of this invention are to provide fluid Q. A second cam is thereby moved intoposition for heating, and the registering device It is utilized in placing the apex of this second apparatus for heat treating in succession a 40 1 n proper alignmen -1'01 heating whenblow' plurality of laterally extending portions of a metal body; to provide apparatus for hardening a cam or a plurality of cams on a camshaft whereby each cam is hardened individually, and

is easily'adjustable to permit treatment of camshafts of and cams of different widths: to provide such apparatus by which a relative reciprocal motion between a cam being and a sourceof-high temperature heat may be elected: to provide such apparatus mm B is onceagain moved into heating position.

The blowpipe ,Bprei'erably directs heatingflames over only a part of the width of the apex of each cam in order to accommodate the narrowest width of. cam which may be treated. Sothattheentirewidthof eachapexwillbe heated. and also to produce a more uniform heating effect, the blowpin .3 preferably is reciprocsted lohgihidin'aily of the camshaft during heating. The blowpipe B is .reciprocatedlongitudinsily of the camshaft an amountsumcient so tlht the upper and lower edges of eachspex wherein mu temperature heating flames are will notbe directly heated but will be heated mm from a blown pe a ai s the mm P m 1 b! conducflonrromthe portio s as.

portionstobehardened,andwhereintheblow-' pipe may be moved away from them being treated and simultaneously therewith supply of gases to the hlowpipe ticaily turned off; toprovide such apparatus wherein 60 p ocation or oscillstionmaybe efiected man- -encyioragreaterammintofhest.tobeconrectly heated. Thiscompensates'forthe tendducted am from the central portion, and prevents the edges from becoming overheated. This ually, or, as illustrated in Fig. 3, by means of a motor M.

As in Figs. 1 and ,2, the support S for-camshaft A includes a vertically-disposed column or I-beam l having an arm ll extending from its lower end, arm ll being provided with a lower center l2 which engages the center hole in the lower end ofcamshaft A. 'An upper arm l4. adjustable upwardly and downwardly along the front flange of column I0, is secured to the flange by a clamping screw l5 and is provided with a movable upper center I6 which engages the center hole at the upper end of camshaft'A. Upper center l6 threadedly engages arm l4, and the into a V notch in indexing plate 34. The V notch in indexing plate 34, of course, corresponds in shape to the apices of the cams of the particular camshaft being treated, and plate 34 may 5 be replaced by other indexing plates having suitable V notches when cams having different configuration are to be treated. The indexing plate 34 may be made of a relatively thin piece of metal, thus being cheaply produced and inex- 10: pensive to carry in stock in large numbers.

The support for blowpipe B comprises an arm 36 provided with a hinged Joint 31 so that the outer end of arm 36 may be moved upwardly and downwardly with respect to its inner end.

vertical position of center .I6 may be adjusted The inner end of arm 36 is pivoted on a pin 38 by a. handle l1. Colinnn i0 preferably is of sufflcient length so that the longest camshaft to be treated may be placed between centers l2 and I6 by properly positioning upper arm l4,

upper center l6 being moved toward or away to secure the blowpipe in any desired radial or from the end of a camshaft in replacing a treated camshaft by an untreated one.v or placing an untreated camshaft in the support. Also, tank T preferably corresponds in depth to the length of column i0, and is embedded in a foundation I8 so that blowpipe B and registering means R will be more accessible to an operator. If desired, tank T may be located in a relatively higher position with respect to the floor or foundation, and a suitable platform upon which an operator may stand provided.

Column I0, during upward and downward movement, is guidedby rollers 20 engaging the rear flange thereof. Rollers 20 are :Iournalled on suitable stub-shafts mounted in vertical plates 2| which are secured to tank T at the rear in any suitable manner, such as by welding. Journalled in the upper end of plates 2| is a shaft 22, to the free or outboard end of which hand- Wheel 1-1 is keyed. Asprocket 23, disposedbetween plates If, is also keyed to shaft 32, and a chain 24 passes over sprocket 23. One end of chain 24 is attached to the bottom of column l6 and the other end is attached to a series of weights 25 which are disposed in a well 26 sunk in foundation l8.

Weights 26, which balance the weight of support S and camshaft A, are removable, a slightly greater number of weights than just sufficient the camshaft preferably being used to prevent lowering when a camshaft is loaded into the machine. This additional weight, of course, will be compensated for as the camshaft moves into the quenching liquid and the liquid exerts a buoyedly engages, a bracket 23 extending forwardly from one of plates 2|. I

As in Fig. 2, the .registering device R includes a lever 3i pivoted on a pin 32 which is mounted on a bracket 33, inturn attached to the side of tank T opposite column l0. An indexing plate 34 is secured to one end of lever 3| and is adapted to engage the apex of a dam to register or align the same in proper position for heating by blowpipe B. With blowpipe B withdrawn to the dotted position of Fig. 2, lever 3| is swung about pin 32 and the camshaft turned about itsaxis so that extending from a bracket 39 attached to the side of tank T adjacent plate 2|. The blowpipe B is secured to the outer end of arm 36 by a clamp 40 which may be tightened by a set screw 4| longitudinal position.

As blowpipe B moves from the heating position (shown in full lines in Fig. 2) to the registering position (shown in dotted lines in Fig. 2), or vice 25 versa, the outer end of arm 36 will be supported by a slide 43, secured to rim 44 of tank T in any suitable manner, such as by welding. Slide 43 extends outwardly from the tank a distance sufficient to permit the blowpipe to be moved far enough away from the camshaft to prevent inter- 5 or dotted position of Fig. 2. .The inner end of slide 43 is provided with a similar flange 46, which, however, is provided with a threaded aperture cooperating with a positioning bolt 41 secured in any desired position by a nut 48. Bolt 4'! acts as an adjustable stop for blowpipe supporting arm 36, to space blowpipe B the proper distance from the cam apex during heating.

A combustion-supporting gas, such as oxygen.

and a combustible gas, such as acetylene, are

45 supplied to blowpipe B by hoses 63 and SI, re-

spectively, which lead from gas-control valve V. Gas-control valve V is mounted on a bracket 62 secured to the side of tank T and is provided with inlet connections 63 on the under side thereto counterbalance the weight of the support and o to which y n and acetylene may be led from suitable sources of supply thereof. Control of the flow of gases through valve V is effected by spring-loaded push buttons 56, i. e. depression of push buttons causes the flow of 55 heating gases to blowpipe B to be initiated, and

release of 'the pressure permits buttons 66 to spring outwardly and the flow of heating gases to be discontinued.

Blowpipe supporting arm 36 is provided with suitable means cooperating with push buttons so that the heating gases will be turned on when blowpipe B is moved into heating position, and turned off when the blowpipe is moved into registering or dotted position of Fig.2. For this pur- 65 pose, an extension 66. formed integrally with or secured to the end of arm 36, is provided with adjustable pins or bolts 61 which actuate push buttons 66. The position of each of bolts 51 is preferably so adjusted that the oxygen will be ,70 shut of! prior to the acetylene, to prevent pure oxygen from passingthrough blowpipe B and attacking the heated surface at the termination of heating.

Blowpipe B includes a body 59 provided with the apex of the cam to be treated will fit exactly valves 60 for controlling the flow of oxygen an acetylene to a suitable mixer'installed within body 59. A fork 6i conveys the combustible mixture to two heads or tips 62 which are provided with suitable outlets for discharging the combustible mixture, to form heating flames which are directed against the surface of the apex lower, which may be secured to the outer pivoted portion of arm 36 in any suitable manner, such as by welding.

Rotation of oscillating cam 13 causes blowpipe support 36 to be reciprocated between suitable limits, as'indicated by the full and dotted posiof the cams being heated. The outlets of eachhead '62 are preferably disposed in transverse parallel rows but placed closer together at one end of each row than at the other end, or dis posed in any other suitable manner, whereby more heat will be applied adjacent the thicker portion of the apex than adjacent the point of the apex.

- This compensates for the tendency for a greater inlet pipe 65 which extends -downwardly to a point adjacent the bottom of tank T, the flow through pipe 65 being controlled by a valve 66.

Valve 66 is preferably left open or slightly open at all times to provide a continuous flow of quenching fluid through the tank, so that fresh,

cool quenching fluid will continually rise to the I top of the tank. To maintain the level of'liq'uid within the tank accurately, and to draw oil heated quenching liquid, a drain or overflow pipe 61 extends upwardly within tank T'to a point just below the top of the tank; warmed cooling liquid overflowing into pipe 61 is removed through a fitting 68, into which pipe. 61 is screwed and which is welded oi otherwise suitably securedto the botto m of tank T in a liquid-tight manner.

As water normally is used.asaquenchingfluid,flt-

ting 68 normally may be connected with a drain or sewer. However, in case special quenching solutions, suchas an aqueous solution of sodium hydroxide, are used, fitting 68 is preferably con-- nected with a suitable pump and cooling coil, if necessary, (not shown) which will return the quenching medium to inlet pipe 65. In either event, a continuous circulation of quenching fluid through tank-T is'assured. I

Further to assure that the quenching liquid at the topof tank -'1 will be suflicientiy cool to ef- 'iect adequate quenching of'the heated surface of each cam apex as it is lowered into the same, .a

bailie 69 is disposed at the surface of the quench- "ing medium. Battle 69 is formed ofsuitable inmotor M will be startedautomatically.

tions of Fig. 3, although the amplitude of oscillation is exaggerated for the sake of clarity'. Since the length of the outer or pivoted portion of arm 36 is a large multiple of the amplitude of oscillation, no particular difficulty will be encountered because heads 62 oscillate in a small segment of an arc, because this segment is substantially a straight line, and. the heads will at all times remain at proper distances from the.

surfaces being heated.

When a different amplitude of oscillation is desired, due to a greater cam-width on the cam-.

shaft being treated, oscillating cam 13 may replaced by another oscillating cam having the desired contour. Oscillating cam13 is preferably made of relatively cheap material, as is indexing plate 38, so that no great expense will be involved in providing diiferent oscillating cams for diiferent widths of cams to be treated.

If more nearly complete-automatic operation is desired} a suitable switch for motor M may be positioned at or adjacent adjustable stop 41, so that when the blowpipe head is moved into heating position, arm 35 will actuate the-switch and The complete operation of the described is as. follows:

Assuming'the supports to be in the vertical position of Fig. 1, to place the first of a series of similar camshafts to be treated in the machine,

the'number'. of weights 25 is adjusted or brake apparatus just bolt 21' screwed inwardly so that the support will not lower when the camshaft is loaded into the machine. Next, clamp I5 is loosened, up'per arm ll moved upwardly, and the lower end of the camshaft'placed upon lower center 12. Then upper arm lids lowered until center I6, when "screwed downwardly, will engage the center hole in. the upper end ofthe camshaft, and so that a camshaft can be replaced without resetting upper arm l4. Clamp i5 is tightened and upper center 16 screwed downwardly against the camshaft with suiflcient pressure so that the camshaft will remain in any radial position, but can be turned easily. Weights 25 are then adjusted, so that,

sulating material, such as Transite board," and is provided with a central aperture ll, sufliciently large to permit the cams to pass the bsille and to the rim of tank-T. when a camthrough. The. baflle is-s'upported by a pluralityof bracket strips 1|, bolted or otherwise suitablyl secured both to shaft to betreated is placed between centers I 2 and I,- column; II is raised suillciently so that lower center I! is at or slightly above the. water level, but not sufficiently so that lower supporting arm llwiilstrike Me I.-

For mechanically oscillating blowpipe B, a motor M, asin-Pig. 3. may be secured to the side of tank 'r by a strap 12. 'Motor 11 m ybe a slowspeed motor, or a higher speed motor providedwith an integral speed-reducer. An oscillating cam II is mounted on the end-ofmotor shaft IQ when free, support S and the camshaft will tend to moveslowly downwardly, and brake 21 adjusted so that a slight efiort is required to raise or lower the camshaft. Wheel H is then turned 'so'that the lowest cam is in approximate verticalposition for treatment..

Registering device R is then swung' into engagement with the cam to be treated and the camshaft turned .or moved radiallyso that the cam is in proper radial position. The cam may also be moved vertically by means of wheel H to the proper vertical position. determined by aligning the top of the cam withthe top of plate 34' or many other suitable manner. ',The constituents of the combustible mixture 5 andthe position of the blowpipe previously. havand engages the lower leg of a Z-shaped cam folin: been adjusted, pilot "I is lightedand the" blowpipe is swunginwardly-until arm 36 strikes bolt ll, i. e to the full position of Fig; 2. The heating gases are automatically turned on as,

pins 51 make push'buttons 55 of valve v, thus initiating heating. During heating. blowpipe B may be oscillated manually, or by'means ofmotor preferably such that theupper and lower edges of the cam apex will not be heated directly, and,

. as stated previously, the heating flames discharged from heads 82 are not directed against the point or tip of the cam apex.

At the expiration of the heating time, normall determined by trial, heating imdiscontinued by moving the blowpipe away to the dotted position of Fig. 2, thus turning of! [the heating gases. Simultaneously, the entire camshaft is lowered so that the heated cam apex will immediately be plunged into the, quenching liquid, the upper portion of which remains cool due to the circulation of cooling medium and also due to the shielding eflect of baflie 6!. As the next cam to be treated will be substantially in the correct vertical position, the cam shaft is turned and the apex registered in correct radial and vertical aligmnent by registering device R, as previously described. The blowpipe B is then swung into heating position, the heating gases automatically turned on, and the operation proceeds as before."

After all of the apices have been hardened in this manner, the camshaft is moved upwardly by means of handwheel H, and the treated cam,- shaft. removed, upper center I! being moved away from the camshaft for the purpose of replacing the treated camshaft by,an untreated one. In case the remaining camshafts to be treated are identical with" the first treated, the entire operation proceeds quickly and smoothly,

' as no further adjustments need be made. Furthermore, for differences in length of camshaft, in cam ramp contour, or in width of cam, the

necessary adjustments of upper arm II, and the replacement of plate 34 and/or oscillating cam II, respectively, are easily and quickly made.

Since only a single cam, (a relatively small portion of the camshaft) is heated at a time, no particular difficulty will be encountered because of expansion or contraction of the camshaft during treatment. Furthermore, since the registering device insures that each cam apex will be placed in the sarne position with respect to the heating heads, and, since each apex is preferably heated for the same length of time, uniform results will be obtained in the case of each cam and each camshaft treated. In addition, uniform cooling of each cam treated is insured by the continucus supply of cool quenching medium to the top quenching liquid Q.

From the foregoing, it will be apparent that this invention provides a'relatively simple and inexpensive apparatus for uniformly duplicating resultsin treating a plurality of laterally ex- 1 tending portions of .an elongated ferrous metal body. Although the treatment of cams upon a camshaft has been described with particularity, it will be evident that the apparatus is suitable for usein the treatment of other metal objects.

Furthermore, various changes may be made in the apparatus without departing from the spirit and scope of this invention.

What is claimed is:

1. In apparatus for heat treating in succession a plurality of laterally extending portions of a metal body, such portions being spaced at different points circumferentially of said body, the combination of means supporting said body for radial movement; means for applying high temperature heat to the surface of a laterallyextending portion, of said body; means supporting said heating means for movement toward and away from such laterally extending portion: means movable toward and away from said body for registering a laterally extending portion in operative position with respect to said'heating means; and means constructed and arranged to effect an intermittent relative movement longitudinally of said body between said body and said heating means, whereby successive laterally extending portions of said body may be moved into operative position with respect to said heating means.

2. In apparatus for heat treating in succession a plurality of laterally extending portions of a metal body, such portions being spaced at different points circumferentially' of said body, the

. combination of means supporting said body:

means for applying high temperature heat to the surface of a laterally extending portion'of said body; means supporting said heating means for movement toward and away from such laterally extending portion; means for registering such laterally extending portion in circumferentially operative position with respect to said heating means; means constructed and arranged to effect a relative movement longitudinally of said body between saidbody and said heating means, whereby successive laterally extending portions of said body may be moved into operative position a with respect to said heating means; and means controlling the operation of said heating means, said supporting means and said controlling means being so constructed and arranged that -heating.is initiated when said heating means is moved toward said body and into heating position and heating is discontinued when said heating means is moved away from' said body.

3. Apparatus for heat treating in succession a plurality of cams upon a camshaft comprising, in combination, means supporting said camshaft with the longitudinal axis thereof disposed vertically; means for applying high temperature heat to a-surface portion of a cam; means supporting said heating means for horizontal movement toward and away from such cam; means constructed and arranged to eflect a downward movement of said camshaft whereby successive cams may be placed in operative position with respect .to said heating means; and means for cooling the heated surface of each cam after heating so as to harden the same.

4. Apparatus for heat treating in succession a plurality of cams upon a camshaft as defined in claim 3, which includes means for exerting a braking effect upon the vertical movement of said camshaft.

5. Apparatus for heat treating in successionand away from said camshaft for registering the laterally extending portion of each cam in operative radial position with respect to said heating means; a body-of quenching liquiddlsposed beneath said heating means: and means constructed and arranged to effect a vertical movement of said camshaft, whereby successive be moved into operative vertical position with with its longitudinal axis disposed substantially vertically; a blowpipe for directing high temperature heating flames against ,a surface portion of a cam; means supporting said blowpipe for horizontal movement toward and away from such cam; means constructed and arranged to effect an intermittent vertical movement of said camshaft whereby successive cams may be placed in operative position with respect to said blowpipe; means for effecting a vertical oscillation of said blowpipe during heating; and means for cooling the heated surface portions of successive cams so as to harden the same.

8. Apparatus for heat treating in successionva plurality of cams upon a camshaft comprising, in combination, means supporting said camshaft with its longitudinal axis disposed substantially vertically; a blowpipe for directing high temperature heating flames against a surface portion of a cam; means supporting said blowpipe for horizontal movement toward and away from such cam, said means comprising an arm pivoted at one end for horizontal movement and hinged for vertical movement of the opposite end thereof; means constructed and arranged to effect a vertical movement of said camshaft wherebysuccessive cams may be placed in operative position with respect to said blowpipe;

means for effecting avertical oscillation of saidblowpipe during heating: and means for cooling the heated surface portions of successive cams so as to harden the same.

9. Apparatus for heat treating in succession a plurality of cams upon a camshaft as claimed in claim 8, in which said means for efiecting a vertical oscillation of said blowpipe comprises means for reciprocating said opposite end of said blowpipe supporting arm.

10. Apparatus for heat treating in'succession the laterally extending portions of a plurality of cams upon a camshaft, comprising, in combination, means for supporting said camshaft forradial movement about its longitudinal axis and with the longitudinal axis of said camshaft disposed in a vertical position; a blowpipe for directing high temperature heating flames against the surface of a laterally extending portion of a cam; means pivoted at a point on one sideof said camshaft and supporting said blowpipe for horizontal movement toward and away from such cam; means pivoted at a point substantially opposite said first-mentioned point with respect to said camshaft. and horizontally movable toward and away from said camshaft, for registering the laterally extending portion of such cam in operative radial position with respect to said heating means; means constructed and arranged to effect a vertical movement of said camshaft, whereby the laterally extending portions of successive cams may be moved into operative vertical position with respect to said blowpipe; and means for cooling the heated'surface portion of successive cams so as to harden the same:

11. Apparatus for heat treating in succession the laterally extending portions of aplurality of cams upon a camshaft as defined in claim 10, which includes means for supplying said blowpipe with a combustible gas and a combustionsupporting gas; a valve for controlling the flow of such gases to said blowpipe; and means attached to said blowpipe supporting means for operating said valve, so as to initiate the flow of such gases to said blowpipe when said blowpipe is moved toward a cam to be treated and into heating position, and to discontinue the flow of such gases when said blowpipe is moved away from such cam.

12. Apparatus for heat treating in succession the laterally extending portions of a plurality of cams upon a camshaft as defined in claim 10, in which said cooling means comprises a tank of quenching liquid disposed beneath said blowpipe and into which a heated cam is lowered,

such apparatus also including an inlet discharging coolingmedium into said tank in the lower portion thereof, and an outlet pipe having an open upper end disposed a relatively short distance below said blowpipe for removing heated quenchnig liquid and maintaining constant the level of quenching liquid in said tank.

13. Apparatus for heat treating in succession the laterally extending portions of a plurality of cams upon a camshaft, comprising, in combination, means for supporting said camshaft; a blowpipe for directing high temperature heating flames against the surface of a laterally extending portion of a cam; means supporting said blowpipe for pivotal movement toward and away from such cam substantially in a plane which is substantially perpendicular to the longitudinal axis of said camshaft; means mounted for pivotal movement toward and away from said camshaft, for registering the laterally extending portion of a cam in operative radial position with respect to said heating means, said registering means also being movable substantially in a plane which is substantially perpendicular to the longitudinal axis of said camshaft; means constructed and arranged to effect a relative movement between said camshaft and said supporting means in the direction of the longitudinal axis of said camshaft, whereby the laterally extending portions of successive cams maybe made to coincide with the plane of movement of said blowpipe; means for effecting a registered; and means for cooling the heated surface portions of successive cams so as to harden the same.

' HOMER W. JONES.

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