US2724394A - Quenching device for heat treating and quenching systems - Google Patents

Description

Nov. 22, 1955, T H SPENCE 2,724,394

QUENCHING DEVICE FOR HEAT TREATING AND QUENCHING SYSTEMS Filed July 23, 1953 3 Sheets-Sheet 1 IN VEN TOR.

c7/ J aarzaar Jzforway Nov. 22, 1955 1- H SPENCER 2,724,394

QUENCHING DEVICE FOR HEAT TREATING AND QUENCHING SYSTEMS Filed July 23, 1953 3 Sheets-Sheet 2 IN V EN TOR.

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Nov. 22, 1955 -r H SPENCER 2,724,394

QUENCHING DEVICE FOR HEAT TREATING AND QUENCHING SYSTEMS Filed July 23, 1953 3 Sheets-Sheet S EI E I N VEN TOR.

BY flg d balzaar' 2,724,394 Patented Nov. 22, 1955 QUENCHING DEVICE FOR HEAT TREATING AND QUENCHING SYSTEMS T H Spencer, Peoria, Ill., assignor to Caterpillar Tractor Co., Peoria, 111., a corporation of California Application July 23, 1953, Serial No. 369,851

3 Claims. (Cl. 134-105) This invention. relates generally to an improved system for heat treating and quenching cylindrical members such as bushings for track rollers of track type tractors, and more specifically to a new and improved quench tube for use in such heat treating and quenching arrangements.

In quenching arrangements in common use the quench tube is usually positioned below the discharge opening of a conventional heating element to receive the heated cylindrical member and the quench tube is usually furnished with an upstanding spray nozzle provided with locating fins, to center said cylindrical member within said quench tube. Water or other suitable quench fluid is injected into said quench tube through a passage in the bottom closure plate of a water jacket surrounding said quench tube and is caused to flood the internal and external areas of the cylinder by a vertical upward flow of quench fluid thereby. Suitable orifices are provided in the quench tube wall to provide free passage of quench fluid therethrough. Uponcompletion of the quenching 1. cycle the cylindrical member is ejected through the top opening of said quenching tube and means is usually provided for deflecting the quenched bushing into a suitable hopper or bin positioned to one side of said arrangement.

The principal disadvantage of the above arrangement is that stagnant areas are created in the quench tube thereby causing a variation in the final hardness of the heat treated member.

It is therefore, a principal object of this invention to provide a heating and quenching arrangement comprising a quenching element that receives the heated member through the top portion thereof; means for detaining the heated member irithe quench chamber during the quenching cycle thereof; and means-for ejecting said quenched member through the bottom portion of the quench tube after the quench cycle is completed; and wherein the quench water is directed downwardly upon all surfaces of said heated member, and a controlled discharge port is provided for permitting a desired flow therethrough; thereby maintaining a desired level of quench fluid within the quench chamber and allowing a steady flow of quenching fluid past the heated member and eliminating any collection of stagnant quench.

Another object of this invention is the provision of a deflecting, grated trough which directs the quenched bushing memberoutwardly of the falling quenching fluid upon completion of such quenching cycle to retain a controlled degree of residual heat within saidbushing to permit a desired stress relief condition. Further and more specific objects and advantages and the manner in which these objects are accomplished will appear in the following specification wherein reference is made to the accompanying drawings.

In the drawings:

Fig. 1 is a schematic view of a heat treating and quenching installation embodying the invention and showing the arrangement of the various components thereof;

2. Fig. 2 is a longitudinal section taken substantially along the lines II-II of Fig. 3 with parts: broken away to show the details of the new quench tube; and

Fig. 3 is a horizontal section taken through the quench tube substantially along the lines III-III of Fig. 2.

With reference to Fig. 1 the new quench tube generally indicated at 10 is disclosed as being positioned below the discharge opening of a heating element of any of the well known types generally indicated at 20. A curved, grated trough 30 is arranged to receive heat treated members such as cylindrical bushings upon completion of the quenching cycle. Upon completion of a heating cycle in the element 20 a heated member such as a bushing 25 will drop into said quench tube 10 and be held therein by a movable stop assembly 35 during the quenching cycle thereof. After a controlled time cycle, a pneumatic piston 40 will be actuated to swing said stop assembly 35 in a clockwise direction to permit the quenched bushing to drop into grated trough 30 which directs said bushing away from the path of the falling quench water to retain a desired amount of residual heat in the bushing for stress relieving as the bushing is directed onto a conveying means or into suitable storage receptacles.

In Fig. 2 the quenching element 10 is disclosed as comprising a receiving tube 11 and a. quenching tube 12, in axial alignment, disposed within a housing 13. An enlarged flange portion 15 of quench tube 12 underlies the lower end of housing 13 and is secured thereto as by capscrews 16. A flange 21 of receiving tube 11 is adapted for sliding engagement with a bore 17 of a bushing 18 carried in the upper end of housing 13. A conically shaped lower end portion 22 of receiving tube 11 is retained in spaced relationship with a matching conically shaped female top portion 23 of quench tube 12 as by a plurality of studs 19 adapted for threaded engagement with the lower side of flange 21 and extending through bores provided in a flange 14 integral with quench tube 12. A plurality of nuts 24, 25 and 26 are provided where by it is possible to make fixed adjustments to the spaced relationship between tube 11 and tube 12 which will be effective to vary the size of conical shaped orifice 27 9 formed between said tubes.

. quently be described.

A multiplicity of radially disposed orifices 41 are formed in the wall of cylindrical portion 28 of quench tube 12 for purposes to be described.

Stop member 35 is disclosed as comprising a stop bar 37 carried on one arm of a bellcrank 38 pivotally secured intermediate its ends, to housing 13 as indicated at 39. Upon the extension of piston 40 bellcrank 38 will rock in a counter-clockwise direction about pivot 39 and position stop .bar 37 beneath chamber 31a to support the bushing to be quenched.

Quenching fluid under pressure is constantly supplied to quenching element It! from an external source, not shown. It enters an annular chamber 51) embracing housing 13, and flows through ports 52 to a reservoir 51 formed between the housing 13 and tubes 11 and 12. Fluid from reservoir 51 is directed downwardly toward the central portion of chamber 31a through the conical orifice 27 and radially toward the center of chamber 31a through orifices 41. The fluid is discharged through the lower end of the quench chan'tberthrough a bore defined by a flange 44 of ring 36.

In operation a heated bushing 25 is dropped from heating elem'ent u'po-n completion-of the heating cycle thereof through a'conical opening'in a director ring 42 retained within a recess 43 of receiving tube 1 1. 'This guides'the'bushin'g through the receiving-tube into the quench where stop bar 37 holds it in the quench chamber as best disclosed in Fig. 2. When a bushing is in contact' with stop bar 37 acontrolle'd discharged opening is defined by the outer diameter of bushing and the inner diameter of flange 44 of ring 36 to retard the flow of discharged quench fluid from the area surrounding the bushing. Stop bar 37 also restricts the discharge of quench fluid from the inside diameter of the bushing during the quenching cycle. The dimensional characteristics of flange 44 and stop bar37 present sufiicient restriction to the discharging fluid to maintain a level of turbulent quench fluid that will immerse the entire inner and outer surfaces of the heated bushing during the quenching cycle.

By controlling the vertical adjustment between conically shaped male portion 22 and comically shaped female portion 23 of tubes 11 and 12 respectively, the quantity of quench directed toward the inside of the bushing can be adjusted as desired and the resulting cone shaped flow of quench water converging centrally of the bushing will insure a steady flow ofquench fluid along the entire inner surface of the bushing.

The orifices 41 are shown as being inclined inwardly and downwardly at the uppermost portion of the quenching chamber and more steeply inclined toward the bottom of the chamber as shown in Fig. 2. This varied inclination provides a desired flow of quench water to the outer surface of the bushing. Quench water introduced through the upper orifices 41 will absorb more heat than that introduced through the lower ones be cause it travelsfarther before being expelled at the bottom of the quench tube. Thus the steeper inclination of the lower orifices will tend to speed up the flow of warmed quench fluid and maintain a relatively constant temperature of quench in contact with the bushing throughout its entire length to insure uniformity of hardness on the finished part.

Upon completion of the quenching cycle, piston 49 is actuated to release the bushing into the grated trough 38 upon which it moves by gravity from beneath the quench area as previously described.

In the system disclosed, all quench fluid flows in a downward path over ail the surfaces of the heated bush ing and the discharge of the quench fluid is controlled to such a point that all surfaces of said bushing will be contacted by a supply of cool quench. Furthermore, due to the constantly moving supply of fluid, air pockets are eliminated; thereby developing an even degree of hardness throughout the entire surface of both the internalv and external walls of said heat treated bushing.

I claim: 1. In a quench fixture for quenching heat-treated bushings or the like, a substantially continuous tubular member, comprising a receiving portionand a relatively enlarged quench chamber, a plurality of radially positioned downwardly disposed ports in the wall of said quench chamber, means to direct jets of cool quench through said ports about the outer surface of a bushing when it is retained in said quench chamber, a conically shaped orifice formed between adjacent ends of said receiving portion and quench chamber for directing a quench spray into the inside of said retained bushing, and a stop memr interposed in the discharge opening of said quench cnur ber forming at least a partial restriction to the discharge flow of quench and maintaining a bath of quench water made turbulent by said jets of quench.

2. In a quench fixture for quenching heat-treated bush ings or the like, a substantially continuous tubular mernoer, comprising a receiving portion and a relatively enlarger! quench chamber, a plurality of radially positioned downwardly disposed ports in the wall of said quench chamber, means to direct jets of cool quench through said ports about the outer surface of a bushing whcn'it is retained in said quench chamber, some of said ports being in the upper portion of the quench chamber and inclined at a slight downward angle and some in the lower portion of the chamber being inclined at a steeper angle to increase the rate of discharge flow of the quench fluid from the upper portion of said quench chamber, and a stop member interposed in the discharge opening of said quench chamber forming at least a partial restriction to the discharge flow of quench and maintaining a bath of quench water made turbulent by said jets of quench, said stop member also acting to retain said bushing within the quench bath and means to move the stop member periodically to permit discharge of the bushing and release of the quench bath.-

3. in a quench fixture for quenching heat-treated bushings or the like, a substantially continuous tubular member, comprising a receiving portion and a relatively eularged quench chamber, a plurality of radially positioned downwardly disposed ports in the Wall of said quench chamber, means to direct jets of cool quench through said ports about the outer surface of a bushing when it is retained in said quench chamber, some or said ports being in the upper portion of the quench chamber and inclined at a slight downward angle and some in the lower portion of the chamber being inclined at a steeper angle to increase the rate of discharge flow of the quench fluid from the upper portion of said quench chamber.

References Cited in the file of this patent UNITED STATES PATENTS Strickland June 12, 1951

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