US2592906A

US2592906A - Speed control valve for hydraulic mechanism

Info

Publication number: US2592906A
Authority: US
Inventors: Emil F Jirsa; Hansen Merlin; Cecil W Bopp
Original assignee: Deere Manufacturing Co
Current assignee: Deere Manufacturing Co
Priority date: 1945-11-05
Filing date: 1948-06-25
Publication date: 1952-04-15
Anticipated expiration: 1969-04-15

Description

April 15, 1952 JIRSA ETAL 2,592,906

SPEED CONTROL VALVE FOR HYDRAULIC MECHANISM Original Filed Nov. 5, 1945 Merlin Hansen Ge 01% M 5 29 Patented Apr. 15, 1952 SPEED CONTROL VALVE FOR HYDRAULIC MECHANISM Emil F. J irsa, Merlin Hansemand Cecil,W.,BopD,,

Waterloo, Iowa, assignors to Deere Manufacturing 00., a corporation of Iowa Original application November 5, 1945, Serial No, 626,626. Divided and this application June 25, 1948, Serial No. 35,214

5' Claims. 1

This invention relates to hydraulic apparatus and more specifically to means for providing a plurality ofoperating means for such apparatus. The present application is a division of our copending application, Serial No. 626,626, filed November-5, 1945 now U. S. Patent 2,532,552.

We have disclosed in that patent a' hydraulic system in which. a manually operated valve selectively controls'the admission of fluid pressure to and the exhaust, of fluid from a fluid motor of the cylinder and piston type. According to a preferred embodiment of the invention, fluid pressure is used tomove the piston for the purpose of accomplishing the. adjustmenwprimarily the raising-of an agricultural implement. In, such systems, the lowering. of the implement isachieved by exhausting the cylinder, the piston and implement moving. by virtue of the weight of theimplement in returning to its previous position. The system disclosed in the application referred to also shows the application, of this type of control means to a cylinder of the two-way type, in which instance fluid pressure is. optionally supplied at either end of the cylinder to accomplish adjustment of the implement in either of two directions. In, either instance, the speed at which the piston moves is controllable by positioning of a valve. A further regulation of the speed of operation of the piston may be accomplished on the low pressure side of the system by regulating the transmission of fluid during the exhaust of the cylinder.

According to the present invention, it is a principal object to-provide improved means for regulating the low pressure side of a hydraulic system. More particularly, it is an object of the invention to provide means that'may be selectively positionable to vary the resistance to. flow of fluid. It is a feature of the invention to provide this meansin the form of a check valve having' an adjustable. portion provided with orifices 4) of difierent sizes, the portion being positionable so that an orificeof acertain size may be selected according to the speed of. operation desired. Still further, it is a. feature of the invention to provide. an improved check valve of, the poppet type, preierably comprising a first valve having a hollow stemand a second valve having a stem fitting in the hollow stem, of the. first valve, the stem of the secondlvalve including a flat selectively communicable with orifices of. different sizes provided in the hollow stem of the first valve.

' 'The foregoing and other desirable objects and features of the invention will become apparent to is made of. a pr ferred orm of the n n n as described in. the following detailed specification and as. illustrated in the accompanying. sheet of drawings in which Figure 1 is, asectional view of a control housing showing a control valve in conjunction with reg latin c k valv s ons ru t d c r n to the invention;

Fi ure 2 is. an enlarged transverse sectional view taken substantially on the. line 2-2 of Figure 1; and

Figure 3 is an end view of the check valve strucraas ie ed alon t e lin n F gur 1 The complete hydraulicsystem is shown in our p nt eierr o b ve a donly s mu h of such system as necessary to illustrate the present invention has been shown and will be described here. Accordingly, the present disclosure is limited to that portion of the main invention including a. control housing 69 which isprovided wtih a cored high-pressure passage 64 having an intake port. 65 which may be connected in any suitable manner to a. source of fluid under pressure, as shown in our copending application. The passage 64 extends upwardly from the port 65 and turns rearwardly at B6 to an enlarged port 61 in a vertically disposed valve cylinder 68, within which is a vertically slidable valve plunger 69. The valve, plunger 69 is provided with a centrally disposed piston or spool 10 disposed within the annular port 61 and substantially coextensive therewith.

The laterally opposite sides of the valve plunger 59 and the upper edges of the piston 10 are ground off, as indicated at H, to provide flat portions along which the fluid can flow. Similarly, the laterally opposite sides of the valve plunger 69 below the piston 10, and the'lower edge of the latter, are grounded as indicated at 12, to pro-' vide passages for the'flow of fluid. Hence,in

the neutral or inactive position of the plunger 6?, as shown in the drawings, the fluid flowing upwardly through the passage 64 and into the port 61 divides betweenthe upper and lower fiat portions H and pans flows therealong through the valve cylinder 68 to a pair of upper and lower annular ports 13 and 14, which are exhaust ports communicating with a reservoir (not shown) within the interior of the control housing 60. Thus, when the control mechanism is inactive, the pump (not shownl furnishes a continuous flow of fluid upwardly through the passages 64 and B6 and along the flats "H and T2 respectively to the ports 13 and 14 and thence to the reservoir those versed in theart as a complete disclosure notshown).

A pair of annular ports 11, 18 are spaced axially above and below the central inlet port 61 in the valve cylinder 68 and these ports are connected to a pair of passages 19, 86, respectively, the outer ends of which are turned upwardly and downwardly at 19 and 60 respectively, and having valve seats or ports 8|, 82 communicating therewith. Poppet-

type valves

83, 84, shiftably carried in

valve bores

83 and 84 are adapted to seat respectively in the valve seats 8|, 82. The

bores

83 and 84 open at their inner ends to the actuating member 69. These check valves are respectively in controlled communication with a pair of cylinder-supply ducts 85 and 86, which are connected by passages (not shown) which in turn may communicate with opposite ends of a fluid motor, as shown in our patent identified above.

It is deemed sufilcient here to state that the ducts 85 and 86 are connected to opposite ends of a fluid motor, such as a cylinder in which a piston is carried for reciprocation. As previously stated, the valve 69 in its neutral position as shown provides for the circulation of fluid from the pump back to the reservoir. When the valve 69 is moved vertically in one direction, fluid under pressure is supplied through one of the ducts 85, 86 to one end of the cylinder and fluid returns from the other end of the cylinder through the other duct 85, 86. The present invention is concerned primarily with the control of fluid returning through that one of the ducts that is operating as an exhaust or return duct at the time, it being an object of the invention, as stated above, to provide means including an adjustable restriction for varying the resistance to the flow of return or exhaust fluid.

Since both

check valves

83, 84 are identical, only one will be described in detail, reference being had to the check valve 83 for a clear view of the external appearance of the valve and reference being had to the valve 84 and the sectional views in Figures 2 and 3 for details of the interior construction of the valve.

Each of the

check valves

83, 84 is a dual valve comprising an outer part I and an inner part I16. The outer part I15 has a valve head I15 seatable on and unseatable from the port or seat 82(8I), and also has a hollow stem I15 which provides an axial bore I11 therein. The outer end of the bore I11 forms a secondary valve seat I11 concentric with or encircled by the port 82(8I) and valve head I15 The stem or carrying port of the inner valve part I16 fits closely but slidably within the bore I11 and has at its outer end means in the form of a small valve head I16 which provides a secondary valve element seatable on and unseatable from the secondary seat 111 The stem I15 of the outer valve part I15 is provided with passage means in the form of three apertures I18, I19, I88, spaced peripherally and extending radially in communication with the passage or bore I11. This construction is best shown in Figures '1 and 2. The stem of the inner valve part I16 is provided with an annular groove I8I under the head I16 and is also provided with passage means by being relieved along one side of the stem, as by grinding a flat portion I82 axially along the stem of the inner valve from the groove I8I to establish communication with any one of the three apertures or orifices I18, I19, and I88. The inner valve part I16 can be rotated about the common axis of the dual valve to place the flat portion I82 selectively in register with any of the apertures I18, I19 or I88, the latter being of relatively different diameters so that the resistance to the flow of oil through the inner valve can thus be adjusted. The two parts I15, I16 are secured in angularly adjusted position by means of a locking washer MP, the latter having a non-circular aperture I83 therein which fits over a correspondingly shaped lug I84 on the valve head 116 of the inner part I16. The locking washer I82 has a radially extending ear I85 which can be inserted into any of three notches 86 in an axially extending flange I81 encircling the head I15 of the outer valve head I15, the three notches I86 corresponding to the position of registry of the three apertures I18, I19 and I89. Each of the

check valves

83, 84 is urged toward closed position by means of a compression spring I86, which bears against the washer I82 and reacts against a plug I89 screwed into a threaded opening I98 in the outer end of the supply passage or duct 85 (86).

Each of the

check valves

83, 84 is actuated by means of a ball I95 disposed at the inner end of the valve, and the balls I95 bear against the splined grooves I96 in the valve plunger 69. The grooves I96 are so inclined that when the valve plunger 69 is moved upwardly, the upper ball I95 is cammed outwardly against the upper check valve 83, while, if the valve plunger 69 is moved downwardly within the valve cylinder 68, the lower ball I95 is forced outwardly to actuate the lower check valve 84. The lengths of the stems of the two coaxial valve parts I15 and I16 are such that the associated ball I95 can engage the inner end of the inner part I16 and shift it outwardlybefore the ball engages the end of the hollow stem I15 of the outer part I15. This reduces appreciably the amount of effort necessary to open either of the check valves, for, if a single valve were to be used in place of one of the dual valves, the oil pressure against the large head would make it very diflicult to raise the valve off its seat; but the area of the small inner valve is so much less than that of a single check valve that the total pressure is greatly reduced. After the inner valve part I16 has been cracked open to unseat the secondary valve I11, the pressure on the head I15 of the outer valve part is reduced sufliciently to make it comparatively easy to open. The balls are thus used as tappets for opening the inner and outer check valve parts, sequentially, and eliminate a considerable amount of the friction and side thrust on the valve stems that would be involved if the inclined camming surfaces on the valve plunger 69 directly contacted the valve stems.

The valve plunger 69 is provided with a pair of spools or pistons I91, I98 at its upper and lower ends, respectively, the inner edges of which are spaced outwardly from the inner edges of the annular ports 13, 14, thus providing for a free flow of oil along the valvecylinder 68 into the exhaust ports 13, 14 when the plunger is in its neutral position. Movement of the valve plunger 69 downwardly moves the upper piston I91 into the upper end of the valve cylinder 68, thereby closing off the upper reservoir port 13. Similarly, when the plunger 69 is moved upwardly, the valve piston I98 acts against the upper edge of the port 14 to close the latter against fiow of oil downwardly into the reservoir.

The lower end of the valve cylinder 68 is threaded, as at 226, to receive a plug 22I in the bottom end of the control housing 60. The

plunger 69 can; beremoved from. the plunger 68 downwardly through the. threaded aperture 229 after the plug 22lhas been: removed. The upper end of the plunger 69 is provided with an upstanding: ear 225 which. is connected by a short link 226 to an arm. 221. east integrally with a hub 228 rigidly fixe'd ona control rockshaft 22.9 which is journaled. in the control housing 68. The rockshaft 229 may be" provided atapoint thereon outside the housing 60' with. a suitable control lever (not shown) which may be manually operated to rock the rockshaft 229 and: thus control positioning of: the valve 69.. The upper limit of movement of the plunger 69 is limited by means of an adjustable limit stop comprising a bolt 235' extending through; a suitably threaded aperturein an arm 236 preferably formed integrally with the hub 228. The threaded end of the-bolt 235 engages a shoulder 231' in the topof the housing 68. A lock nut 238- is provided on the bolt 235 for locking. the latter in adjusted position. A cover plate 239 closes the opening defined by the shoulder'231 in the top of the housing 60 and maybe removably secured in place by any appropriate securing means. Various other details and refinements of design in connection with the valve 69' and the control thereof are shown in the co-pending applications referred to above and need not be further illustrated or described here.

The operation of the mechanism is as follows: Movement of the plunger" 69 upwardly brings the lower'piston portion. I98 into closing relation with the edge of the exhaust port 14 and simultaneously moves central. piston; portion Til upwardly to cut oil. the flow of oil upwardly through the valve cylinder 68. This flow is not reduced abruptly, however, in view of the fact that the edge of the piston portion 111 is ground ofi on an arc 2lll', with the result that the upa ward flow of oil to the cylinder 68 is not entirely out off until the lower'point on the curved edge 291 coincides with the upper edge of thecentral port 61. The lower portion of the piston 18 is similarly provided with a cut-off as indicated at 202.

To continue, during the gradual cut-ofi of the oil flow to the reservoir, the pressure increases in the high pressure duct 64 and in the lower portion of the valve cylinder 68 beneath the inlet port 61. This causes the oil to flow along the flat portion I2 of the plunger 69"and through the port 18 and passage 88, thereby forcing the check valve 84 away from. the seat 82 against the pressure of the spring I88. The oil then flows through the supply duct 86 and thence to whatever kind of fluid motor is utilized with the system.

The upward movement of the valve plunger 69 has also forced the inclined surface of the groove I96 against the ball I95 to open the upper check valve 83. If the cylinder and piston with which the control system is utilized is of the two-way type, fluid returning from the end of the cylinder opposite to that to which fluid pressure is applied through the duct 86 will return through the duct 85 and through the open check valve 83. Since initial movement of the valve 69 upwardly causes the ball I95 to first engage the stem of the inner check valve part I16, the resistance to the flow of oil through the open check valve 83 will be determined by whichever of the apertures I18, I19 or I80 is in register with the flat I82 on the valve part I16. In the drawings, the aperture I19 of medium size is so registered. A

- similar result is achieve'd, of: course;.ini the: supply of fi'uidi under pressure through; the passage 88, check valve 84,. and; duct. 86, since the initial rise of pressurelinthe valve cylinder below the piston 10'will force fluid througlrthe aperture I19, along the hat I82 and. against the. head of the inner valve: part I16. However, further: upward: movement of the valve plunger: 69 causes the ball I95 to engage the inner end of. the stem I15 'of: the outer valve: part I15 thus fully opening the check valve 83 to the exhaust fluid. At the same time, the pressure rise in. the valve cylinder. 68 below the piston 18' now fully opens the lower. check valve 84- against the spring I88, thus imparting full speed: operation to the fluid. motor that is connected to the control system. Movement of the valve plunger 69 downwardly from its neutral position results in the reversal of the system, the upper duct 85n0w being a supply duct and thelower' duct 86 constituting a return duct. In the case of a fluid motor of the single-action or one-way type, only one of the ducts 85, 86 is used andwhicheve'r one is used serves the dual function of a supply and a return duct. However, the results are similar to those described above.

Either of the plugs I89 canbe removed for the purpose of providing for access to the check valves 83', 84, so that the inner valve part I16 may be rotated with respect to the outer valve part I15 to dispose th'eflat- I82 in register with a selected one of the apertures I18; I19'or I;

The foregoing is based upon a preferred enrbcdiment ofpur'inventi'ont It should be understood, of course, that various modifications and alterations may be made in the preferred form of the invention without departing from the spirit and scope of the invention as defined in the appended claims.

What is claimed is:

1. In fluid pressure mechanism, a dual valve comprising a first poppet type valvehaving a recess extending through the valve head into the stem thereof, a second poppet valve seated in said recess and having a stem fitting closely but slidably within the recessed stem of said first valve, said second valve stem being relieved axially along one side to provide for the flow of fluid under the head thereof and along the stem, said recessed stem of said first valve having a plurality of peripherally spaced, radially extending apertures of relatively different sizes communicating' with the recess in said stem, said second valve being adjustable angularly about its axis to position the axially relieved portion in register with any or said apertures, selectively, and means for retaining said second valve in angularly adjusted position during operation.

21 In fluid pressure mechanism, a dual valve comprisingafirst poppet type valve having a hollow stem and a head mounted thereon and having a valve seat in said head, and a plurality of peripherally spaced, radially extending apertures of difierent sizes in the stem communicating with the hollow interior thereof, a second poppet type valve having a head adapted to cover said seat and a stem extending through the hollow stem of said first valve, said second stem having an enlarged portion adapted to block all but one of said apertures and adjustable angularly relative to said hollow stem to select one of said apertures for conducting fluid therethrough, and means for retaining said valve in adjusted position. v

3. In fluid pressure mechanism, a dual valve including a first poppet type valve comprising a stem having a passage extending axially therethrough and a head at one end of said stem, said head being recessed to provide a peripheral flange and provided with a valve seat in one end of said passage, said stem being provided with a plurality of peripherally spaced, radially extending apertures of relatively different sizes communicating with said passage, a second poppet type valve having a head seated in said seat and a stem extending through said passage and fitting closely but slidably and adjustable angularly within the passage, said second valve stem being relieved under the head thereof and axially along one side to provide for the flow of fluid between said seat and one of said apertures selected by angular adjustment of said second valve relative to said first valve about its major axis to position the axially relieved portion in register with any of said apertures, selectively, and a retaining member engageable with said second valve head and rotatable therewith and having an ear extending over said flange in said first valve, said flange having notches adapted to receive said ear in any one of the various positions of said second valve.

4. In fluid pressure mechanism, a dual valve structure comprising a first valve having a body and a head fixed thereto, the head having a seat therein and the body bein provided with a hollow interior communicating with the seat, the body further having a plurality of apertures of different sizes spaced angularly about the axis of the body and communicating the exterior of the body with the interior thereof; a second valve having a carrying part and a head part fixed thereto, and arranged with the carrying part in and slidable lengthwise of the hollow body of the first valve and angularly adjustable on the axis about which the apertures are spaced, and with the head part seatable on and unseatable from the seat in the first valve head, said carrying part having a portion thereof within the hollow body of the first valve provided with such cross-sectional shape as to block one of said apertures while leaving another of said apertures open to establish fluid communication via such open aperture between the exterior of the first Valve and the seat of the first valve, said second valve being angularly adjustable as aforesaid to re-position said portion to respectively block and open different apertures; and means cooperative between the valves for fixing the second valve in a selected position of angular adjustment.

5. For use in a, valve casing having a valve bore including an outer portion providing a primary port and an inner portion opening to a valve-actuating meinber: a dual valve, comprising, an outer part adapted to be shiftably carried in the valve bore and having inner and outer ends and provided with a through bore communicating said ends, said bore at its outer end providing a secondary valve seat in said part; means at the outer end of said part including a valve head seatable on and unseatable from the aforesaid port, and means at the inner end of said part engageable by the valve-actuating member to efiect shifting of said part for causin unseating of said valve head; means at the outer end of said part including a secondary valve element seatable on and unseatable from said secondary valve seat; an inner valve part axially shiftable in the outer part bore but fitting said bore intermediate its opposite ends sufiiciently closely to substantially seal said bore against the transmission of fluid between its ends, said inner part having an outer end portion engageable with said secondary valve element, and an inner end normally projecting axially inwardly beyond the inner end of the bore so as to be initially engageable for operational shifting by the valve-actuating member prior to engagement of said member with the inner end of the outer part; passage means in the outer part, and passage means in the inner part; the passage means in the outer part being spaced axially inwardly of the valve head, and the passage means in the inner part opening generally axially to the outer end of the bore and communicable with said outer part passage means; said inner part being constructed for adjustment relative to the outer part other than by said operational shifting thereof and having provision for the projection of an end portion thereof axially inwardly of the inner end of said bore to the same extent as aforesaid to maintain the capacity of the inner part for initial engagement and operational shifting by the valve-actuating member regardless of such adjustment; and the passage means in at least one part bein constructed to provide a plurality of different fluid restrictions and selectively cooperative for communication with the passage means in the other part incident to adjustment of said inner part.

EMIL F. JIRSA.

MERLDT HANSEN,

CECIL W. BOPP.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Allen Apr. 15, 1944