US3583585A - Hydraulic control system for a backhoe - Google Patents

Hydraulic control system for a backhoe Download PDF

Info

Publication number
US3583585A
US3583585A US831905A US3583585DA US3583585A US 3583585 A US3583585 A US 3583585A US 831905 A US831905 A US 831905A US 3583585D A US3583585D A US 3583585DA US 3583585 A US3583585 A US 3583585A
Authority
US
United States
Prior art keywords
stick
cylinder
fluid
bucket
boom
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US831905A
Other languages
English (en)
Inventor
Arthur B Joyce
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Dana Inc
Original Assignee
Tyrone Hydraulics Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tyrone Hydraulics Inc filed Critical Tyrone Hydraulics Inc
Application granted granted Critical
Publication of US3583585A publication Critical patent/US3583585A/en
Assigned to DANA CORPORATION A CORP OF VA reassignment DANA CORPORATION A CORP OF VA MERGER (SEE DOCUMENT FOR DETAILS). Assignors: TYRONE HYDRAULICS, INC. A DE CORP.
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
    • F15B11/17—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors using two or more pumps
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F3/00—Dredgers; Soil-shifting machines
    • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
    • E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
    • E02F3/36—Component parts
    • E02F3/42—Drives for dippers, buckets, dipper-arms or bucket-arms
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F3/00—Dredgers; Soil-shifting machines
    • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
    • E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
    • E02F3/36—Component parts
    • E02F3/42—Drives for dippers, buckets, dipper-arms or bucket-arms
    • E02F3/43—Control of dipper or bucket position; Control of sequence of drive operations
    • E02F3/435—Control of dipper or bucket position; Control of sequence of drive operations for dipper-arms, backhoes or the like
    • E02F3/437—Control of dipper or bucket position; Control of sequence of drive operations for dipper-arms, backhoes or the like providing automatic sequences of movements, e.g. linear excavation, keeping dipper angle constant
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E02F9/2221—Control of flow rate; Load sensing arrangements
    • E02F9/2239—Control of flow rate; Load sensing arrangements using two or more pumps with cross-assistance
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E02F9/2278—Hydraulic circuits
    • E02F9/2292—Systems with two or more pumps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/205—Systems with pumps
    • F15B2211/20576—Systems with pumps with multiple pumps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/305—Directional control characterised by the type of valves
    • F15B2211/30505—Non-return valves, i.e. check valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/305—Directional control characterised by the type of valves
    • F15B2211/3056—Assemblies of multiple valves
    • F15B2211/3059—Assemblies of multiple valves having multiple valves for multiple output members
    • F15B2211/30595—Assemblies of multiple valves having multiple valves for multiple output members with additional valves between the groups of valves for multiple output members
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/31—Directional control characterised by the positions of the valve element
    • F15B2211/3105—Neutral or centre positions
    • F15B2211/3116—Neutral or centre positions the pump port being open in the centre position, e.g. so-called open centre
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/405—Flow control characterised by the type of flow control means or valve
    • F15B2211/40515—Flow control characterised by the type of flow control means or valve with variable throttles or orifices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/42—Flow control characterised by the type of actuation
    • F15B2211/428—Flow control characterised by the type of actuation actuated by fluid pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/45—Control of bleed-off flow, e.g. control of bypass flow to the return line
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/50—Pressure control
    • F15B2211/57—Control of a differential pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/605—Load sensing circuits
    • F15B2211/6051—Load sensing circuits having valve means between output member and the load sensing circuit
    • F15B2211/6054—Load sensing circuits having valve means between output member and the load sensing circuit using shuttle valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
    • F15B2211/71—Multiple output members, e.g. multiple hydraulic motors or cylinders
    • F15B2211/7142—Multiple output members, e.g. multiple hydraulic motors or cylinders the output members being arranged in multiple groups
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
    • F15B2211/78—Control of multiple output members
    • F15B2211/781—Control of multiple output members one or more output members having priority

Definitions

  • ABSTRACT A hydraulic control system for a backhoe having a pivoted boom, stick and bucket, and which control system includes a pair of pumps, valves, and related conduits for directing the hydraulic fluid in such a manner that when the claimss Drawing Figs digging resistance is above normal during digging movement U.S. Cl. 214/138, of the stick, the fluid first causes curling of the bucket to try to 214/762, 37/103 relieve the abnormal resistance and then if not relieved, the Int. Cl B66f 9/22 fluid then causes lifting of the boom to further relieve the re- Field of Search 214/138, sistance.
  • a modified embodiment is shown which utilizes one 762; 37/103 pump.
  • U.S. Pat. No. 3,339,763 discloses an. automatic backhoe control system in which there is means responsive to overload pressure-in the crowd jack 24 for directing fluid under pressure to the curl jack 26 to causepivoting of the bucket to decreased digging attitudes, and means responsive to simultaneous overload pressure in the crowd jack 24xand curl jack 26 for directing fluid under pressure to the lift jack 2 2 to cause pivoting of the lift arm to decreased digging attitudes.
  • U.S. Pat. No. 3,414,146 also discloses an automatic backhoe unit somewhat similar to that of the U.S. Pat. No. 3,339,763 and which also employs a great number of valves and circuits, as will be seen from reference to FIGS. 2a, 2b, and 2c of the U.S. Pat. No. 3,414,146 Also, this patent utilizes a single hydraulic source, namely, pump 72 which is directed to perform the various functions of automatically relieving the overload pressure during digging by means of the various valves shown. In addition, the U.S. Pat. No. 3,414,146 is directed towards utilizing manual means for overruling the automatically actuated pilot operated valves.
  • the present invention is directed towards overcoming the disadvantages and problems relative to previous hydraulic control systems for backhoes.
  • the concept of the present invention is to provide a highly effective and relatively simple hydraulic control system in which there is smooth operation and hydraulic power is provided in the particular places in the system where needed and at the proper time.
  • Applicant accomplishes this concept by providing a pair of hydraulic fluid delivery means, namely, first and second fluid delivery means for supplying hydraulic fluid under pressure.
  • means is provided for selectively directing the hydraulic fluid from both said first delivery means and said second delivery means to the stick cylinder to cause the stick to move in a digging direction when the fluid pressure in the stick cylinder is below a predetermined amount and for directing-the.
  • means is provided for directing a portion of the hydraulic fluid from said second delivery means to the lift cylinder to cause the boom to lift when the fluid pressure in the bucket cylinder is above a predetermined amount.
  • a ditch can be dug which has a level bottom even when unskilled personnel are used.
  • Another feature of the present invention is to provide means for preventing chattering of the device during retracting or dumping motion of the bucket or the stick.
  • FIG. 1 is a sideelevational view of a backhoe in which the hydraulic control system of the present invention is provided, and which is shown in the process of digging a ditch.
  • FIG. 2 is a schematic diagram of the hydraulic control system of the present invention and the related parts of the backhoe to which the hydraulic system is coupled.
  • FIG. 3 shows a modification of a portion of that shown in FIG. 2.
  • Backhoe 13 typically includes a vehicle or tractor 15 having the usual engine 17, mounted on a chassis or frame 19, crawlers 21, andother suitable components typically found on a backhoe.
  • backhoe 13 includes the usual lift arm or boom 23 pivotally mounted adjacent the inner end 23a thereof as at 25-from chassis 19.
  • a ram or boom cylinder 27 is pivotally attached to chassis 19 as at 29 and pivotally attached adjacent the other end as at 31 to boom 23 so that retraction of boom cylinder 27 causes downward pivoting of the boom and extension of the boom cylinder 27 causes upward pivoting of the boom.
  • a crowd arm or stick 33 is pivotally mounted adjacent the inner end 33a thereof as at pivot point 35 to boom 23 adjacent the outer end 23b thereof.
  • the crowd or stick cylinder 37 is pivotally attached at one end thereof as at 39 to boom 23 and pivotally attached at the opposite end thereof as at 41 to stick 33 for pivoting stick 33 in an inwardly or digging motion or disposition (clockwise as viewed in FIG. 1) when stick cylinder 37 is extended and for pivoting the stick 33 in an upwardly or retracting disposition (counterclockwise as viewed in FIG. 1) when cylinder 37 is retracted.
  • a bucket 43 is pivotally attached as at 45 to stick 33 adjacent-the outer end 33b of the stick.
  • a curl or bucket cylinder 47' is coupled to bucket 43 adjacent one end of the cylinder and is pivotally attached as at 51 to stick 33 for pivot of the bucket 43 relative to stick 33 in an inwardly curling motionor disposition (clockwise as viewed in FIG. 1) when cylinder 47 is extended and for pivot of the bucket in a retracting motion or disposition (counterclockwise as viewed in FIG. 1) when cylinder 47 is retracted.
  • hydraulic control system 11 includes a first fluid delivery means 53 including a first fluid conduit 55 and means providing fluid under pressure thereto, which preferably includes a first pump 57 receiving hydraulic fluid from tank 59 through the branch 61a of the supply conduit 61.
  • Pump 57 is of any suitable type, such as a gear pump, coupled to and driven by engine 17.
  • a second fluid delivery means 63 is provided which includes an output line 65 having branches 65a and 65b and means providing fluid under pressure thereto including a second pump 67' which receives fluid from the tank source 59 through the second branch 61b of supply conduit61.
  • Second pump 67 is similar to pump 57 and preferably is also driven by engine 17. It will be understood that pumps 57, 67 may be either two separate pumps, or a double pump with two pump sections on the same shaft, or if desired, may be any two other means for providing fluid under pressure to the respective conduit or lines 55, 65.
  • a first pilot operated control valve 69 is provided which senses the pressure in first conduit 55 through the line 71 and is operative in two positions depending upon the pressure in first conduit 55. Thus, when the pressure in first conduit 55 is below a predetermined amount, the valve 69 will be in a first condition shown in FIG. 2, and when the pressure in conduit 55 is above a predetermined amount, valve 69 will shift to the left as viewed in FIG. 2. When valve 69 is in said first position, the fluid from branch 65!) will be directed by the valve through the line 650 to the first conduit 55 so that the output from the combined pumps 57 and 67 will be provided in first conduit 55. First conduit 55 leads to the manual control valve means 73 for directing the hydraulic fluid to the bucket cylinder 47 and stick cylinder 37.
  • Manual control valve means 73 is of any suitable construction and preferably as shown in FIG. 2 wherein there are two three-way valves, a control valve 75 for bucket cylinder 47 and a control valve 77 for stick cylinder 37.
  • the arrangement of the various conduits are preferably as follows: First conduit 55 connects to a port 79 on valve 75.
  • a conduit 81 leads from a port 83 on valve 75 to a port 85 on valve 77.
  • a conduit 87 leads from port 89 on valve 77 to tank 59.
  • a conduit 91 leads from a port 93 of valve 75 to the front or rod end of bucket cylinder 57.
  • a line 95 leads from a port 97 of valve 75 to the base end of bucket cylinder 47.
  • a conduit 99 leads from a port 101 of valve 77 to the base end of stick cylinder 37 and a line 103 leads from a port 105 of valve 77 to the front or rod end of stick cylinder 37.
  • valve 75 when the left end of valve 75 is moved into position in alignment with the ports, the hydraulic fluid will be caused to move through the valve and the line 91 to the front or rod end of the bucket cylinder 47 to cause bucket 43 to move in a retracting or unloading motion.
  • a second conduit 107 leads from an outlet port 109 of first pilot operated control valve 69 with one branch 107a thereof leading to the base end of bucket cylinder 47 through the conduit 95 and another branch 107b leads to an inlet port 111 of a second pilot operated control valve 113.
  • a check valve 115 is provided in branch 107a to prevent reverse flow of fluid therethrough to the other portions of the second conduit 107.
  • Second pilot operated control valve 113 is similar to first pilot operated control valve 69 and is operative responsive to the pressure in conduit 107a as communicated to the end of the valve spool through the line 117.
  • Second pilot operated control valve 113 is a two position valve in which the valve is movable from and to a first position or condition as shown in FIG.
  • a third conduit 119 leads from a port 121 in valve 113 to the base end of boom cylinder 27.
  • a line 121 leads from the front or rod end of boom cylinder 27 to the port 123 of second pilot operated valve 113.
  • a line 125 leads from port 127 of second pilot operated valve 113 to tank 59.
  • a manual control valve 127 is provided for boom cylinder 27 as well as a third fluid delivery means 129 including a fluid line 131 and means providing fluid under pressure thereto, which preferably includes a third pump 133 receiving hydraulic fluid from tank 59 through the supply conduit 135.
  • Pump 133 is of any suitable type, such as a gear pump, and is preferably coupled to and driven by engine 17, by suitable means, not shown.
  • Line 131 leads to port 137 of valve 127 and a line 139 leads from port 141 of valve 127 to tank 59.
  • a line 143 connects port 145 of valve 127 to line 121 which in turn leads to the front or rod end of boom cylinder 27, and a line 146 leads from port 147 of valve 127 to line 119 which in turn leads to the base end of the boom cylinder 27.
  • Manual control valve 127 is similar to valves 75 and 77 and is a three-position valve with the center position being shown in FIG. 2 wherein flow is blocked from pump 133 to the boom cylinder 27 and caused to return to tank 59 through lines 131 and 139.
  • valve 127 When valve 127 is shifted to align the right portion of the valve with the ports 145, 137 and 147, 141 it will be understood that fluid flow is directed from line 131 through the valve, through line 143 and 121 to the rod end of the boom cylinder 27 to cause lifting of the boom 23.
  • the left end portion of the valve 127 When the left end portion of the valve 127 is shifted to line up with the ports, it will be understood that the fluid flow will be to the front end of the boom cylinder 27 to cause lowering of the boom 23.
  • first pilot operated valve 69 is provided with a pilot operated relief valve 148 and a two-way manual or solenoid operated valve 149.
  • the first pilot operated valve 69 is unlocked, whereas, when the valve is in the other position to block flow through the line 150 in which the valve is interposed, then fluid is trapped at the end of the spool of valve 69 so that it cannot shift to the left.
  • second pilot operated valve 113 is provided with a pilot operated relief valve 153 and manual or solenoid operated valve 155 which operate in the same manner as relief valve 148 and valve 149.
  • Another pilot operated valve 157 is provided downstream of valve 155 whereby when the valve 155 is in a first position, as shown in FIG.
  • the hydraulic system 11' is in a first mode of operation so that in order to shift the pilot operated valve 113 into said second condition thereof, the pressure in line 117 must be above the combined pressures required to operate valves 153 and 157.
  • valve 155 When valve 155 is moved to the second position in which the right portion of valve 155, as viewed in FIG. 2, is in line with the ports, the flow bypasses valve 157 and flows directly to the tank through the line 160 so that the hydraulic system 11 is in a second mode of operation in which the pressure in line 117 need only be greater than the operating pressure of valve 153 in order to shift valve 113.
  • the operating pressure of relief valve 153 should be less than the reactive forces operating on bucket 43 so that when valve 155 is in said second position, abnormal resistance on the stick 33 during the digging operation will cause lifting of boom 23 rather than curling of bucket 43, which will be better understood in the description to follow later in the specification
  • These two modes of operation provide for the digging of ditches with smooth bottoms, which will also be better understood in the description to follow later.
  • a shuttle valve 161 is provided in connection with first pilot operated valve 69 so that when the bucket 43 and/or stick 33 is being moved in retracting or dumping motions, the valve 69 is locked in said first position which prevents chattering during the retracting or dumping cycle of the bucket 43 or stick 33. More particularly, one end of the shuttle valve 161 is coupled to the rod end of stick cylinder 37 through line 163 and line 103 to which line 163 is coupled. Thus, when there is high pressure on the rod end of the stick cylinder 37 (during retraction of the stick 33), the high pressure causes the shuttle valve 161 to block flow from line 150 and consequently blocks the fluid from the end of the first pilot operated valve 69 and locks the valve in said first position thereof.
  • shuttle valve 161 is connected through a line 165 and line 167 to line 91 which in turn is connected to the rod end of bucket cylinder 47 so that when there is high pressure in line 91 (when bucket 43 is retracting or dumping) this causes the high pressure to be felt'at shuttle valve 161 and causes the shuttle valve to block flow from line 150 and lock the first pilot operated valve 69 as heretofore described relative to the other action of the shuttle valve.
  • shuttle valve 161 is an or" valve which blocks the flow from line 150 if there is high pressure in the rod end of the stick cylinder 37 or the bucket cylinder 47.
  • Line 167 also leads to port 169 of the first pilot operated valve 69 so that when the valve 69 is in said second position, fluid can flow through valve from line 167 and through line 171 to tank 59.
  • both pumps 57 and 67 will be pumping hydraulic fluid through first conduit 55, line 81, and line 99 to the base end of the stick cylinder 37, causing the stick cylinder 37 to extend.
  • the above conditions will continue to exist.
  • the pressure buildup in line 99 will be felt in first conduit 55, which will cause the first pilot operated valve 69 to shift to said second position by virtue of the pressure being exerted to the left through the line 71 from first conduit 55. This will cause the hydraulic fluid from pump 67 to flow through second conduit 107 and only the fluid from pump 57 to flow through first conduit 55.
  • the fluid flow through second conduit 107 will flow to the base end of the bucket cylinder 47 through the line 95 to cause the bucket cylinder 47 through the line 95 to cause the bucket to move in a so-called curling" disposition (or clockwise as viewed in FIG. 2) in which disposition the bucket is disposed at an angle so that the digging is easier.
  • the cylinder 47 extends to cause pivoting of the bucket 43 to an angle which causes less resistance to movement through the earth.
  • ground resistance to the movement of stick 33 decreases which causes a lessening of the pressure in line 99 that is reflected in first conduit 55 to cause the valve 69 to move back to said first position so that the pumps 57 and 67 are pumping once more through first conduit 55, and there is no fluid going to the bucket cylinder 47.
  • second pilot operated valve 113 When the ground resistance is so great that a curling operation as above described will not decrease the ground resistance to the movement of stick 33, second pilot operated valve 113 will move to said second position or the left, so that the hydraulic fluid will flow from branch 107k and line 119 to the base end of the boom cylinder 27. This will cause the boom 23 to lift or move in an elevating motion and thereby decrease the ground resistance to the movement of stick 33, which again will cause the valve 113 and valve 69 to move into said first positions, and both of the pumps 57, 67 to flow into first conduit 55 and to the stick cylinder 37.
  • the heretofore described second mode of operation of system 11 is employed by shifting valve into said second position after the upper part of the ditch has been dug by means of the system being in said first mode of operation.
  • the valve 155 is shifted into said second position so that rather than curling the bucket 43, the boom 23 will lift as the stick 33 is moved in a digging disposition to keep the lower end of the bucket 43 along substantially the same level so that the bottom B of the ditch remains horizontal.
  • FIG. 3 which is substantially the same as that shown in FIG. 2, except that a single pump 173 is provided instead of the two pumps 57, 67.
  • the output line 175 of pump 173 branches into the two branches 175a and 17517 and leads to the pilot operated valve 69.
  • Second pilot operated valve 113 which corresponds to valve 113 of FIG. 2, is provided with means for placing the hydraulic system in a first or second mode of operation so that the system of FIG. 3 will function in a similar manner to that of FIG. 2.
  • a pilot operated valve 153' is provided which corresponds to valve 153 of FIG. 2.
  • an arrangement is provided in FIG.
  • valve 177 (either manual or solenoid operated) is in series with a pilot operated relief valve 179 and said series (177, 179) is in parallel with valve 153' so that when valve 177 is in one position, the system is in a first mode of operation and when valve 177 is in the other position, the system is in a second mode of operation.
  • the remaining parts are the same as shown in FIG. 2 with the same numbers being given to corresponding parts, and the lower portion of the schematic diagram, which is the same as FIG. 2, has been broken away. It will be understood that the parallel-series arrangement of FIG. 3 may be utilized in the system of FIG. 2 and the series arrangement of FIG. 2 may be utilized in the system of FIG. 3 without departing from the spirit and scope of the present invention.
  • a hydraulic system for a backhoe including a vehicle, a boom pivoted to said vehicle, a stick pivoted to said boom, a bucket pivoted to said stick, a boom cylinder for pivoting said boom relative to said vehicle, a stick cylinder for pivoting said stick relative to said boom, and a bucket cylinder for pivoting said bucket relative to said stick; said system comprising a first hydraulic fluid delivery means for supplying hydraulic fluid under pressure, a second hydraulic fluid delivery means for supplying hydraulic fluid under pressure, means for selectively directing the hydraulic fluid from both said first delivery means and said second fluid delivery means to said stick cylinder to cause said stick to move in a digging direction when the fluid pressure in said stick cylinder is below a predetermined amount and for directing the hydraulic fluid from said first delivery means to said stick cylinder and the hydraulic fluid from said second delivery means to said bucket cylinder to cause said bucket to move in a curling direction when the fluid pressure in said stick cylinder is above a predetermined amount, and means for directing a portion of the hydraulic fluid from said second delivery means to said
  • a hydraulic system for a backhoe including a vehicle, a boom pivoted to said vehicle, a stick pivoted to said boom, a bucket pivoted to said stick, a boom cylinder for pivoting said boom upwardly and downwardly, a stick cylinder for pivoting said stick selectively in inwardly digging motions ad outwardly retracting motions, a bucket cylinder for selectively pivoting said bucket relative to said stick in inwardly curling motions and outwardly retracting motions; said system comprising a first hydraulic fluid delivery means for supplying hydraulic fluid under pressure, and a second hydraulic fluid delivery means for supplying hydraulic fluid under pressure; a first three-way control valve means selectively for blocking hydraulic fluid flow when in a first position, for directing the fluid to one end of said stick cylinder to cause pivot of said stick cylinder in said digging motions when in a second position, or for directing the fluid to the opposite end of said stick cylinder to cause pivot of said stick in said retracting motions when in a third position; a second three-way control valve
  • the hydraulic control system of claim 2 which includes a third hydraulic fluid delivery means for supplying hydraulic fluid under pressure; a third three-way control valve means selectively for blocking the fluid flow from said third fluid delivery means to said boom cylinder when in a first position, for directing the fluid flow from said third fluid delivery means to one end of said boom cylinder to cause pivot of said boom upwardly when in a second position, or for directing the fluid flow from said third fluid delivery means to the opposite end of said boom cylinder to cause pivot of said boom downwardly when in a third position.
  • a hydraulic system for a backhoe including a vehicle, a boom pivoted adjacent one end of said vehicle, a stick pivoted adjacent one end of said boom adjacent the end thereof remote from said vehicle, a bucket pivoted to said stick adjacent the end thereof remote from said boom, a boom cylinder for pivoting said boom upwardly and downwardly relative to said vehicle, a stick cylinder for pivoting said stick selectively in inwardly digging motions and outwardly retracting motions, a bucket cylinder for selectively pivoting said bucket relative to said stick in inwardly curling motions and outwardly retracting motions, and first control valve means for directing fluid to said stick cylinder for movement of said stick in digging motions; said system comprising a hydraulic fluid source, a first pump means and a first conduit means for supplying fluid from said source to said first control valve means, first pilot operated valve means shiftable between a first condition responsive to the hydraulic pressure in said first conduit being below a predetermined amount when the digging motion of said stick is normal and a second condition responsive to hydraulic pressure in said first conduit
  • a hydraulic system for backhoe including a vehicle, a boom pivoted to said vehicle, a stick pivoted to said boom, a bucket pivoted to said stick, a boom cylinder for pivoting said boom relative to said vehicle, a stick cylinder for pivoting said stick relative to said boom, and a bucket cylinder for pivoting said bucket relative to said stick; said system comprising hydraulic fluid delivery means for supplying hydraulic fluid under pressure, means selectively operable in a first mode or a second mode of operation for directing the fluid from said fluid delivery means only to said stick cylinder to cause said stick to move in a digging motion when the fluid pressure in said stick cylinder is below a predetermined amount, for directing at least a portion of said fluid from said fluid delivery means to said bucket cylinder to cause said bucket to move in a curling direction when the fluid pressure in said sticl cylinder is above a predetermined amount and when said selectively operable means is in a first mode of operation, and for directing at least a portion of said fluid from said fluid delivery means to said bucket cylinder
  • a hydraulic system for a backhoe including a tractor, a boom pivoted to said tractor, a stick pivoted to said boom, a bucket pivoted to said stick, a boom cylinder for pivoting said boom upwardly and downwardly relative to said tractor, a stick cylinder for pivoting said stick selectively in inwardly digging motions and outwardly retracting motions, and a bucket cylinder for selectively pivoting said bucket relative to said stick in inwardly curling motions and outwardly retracting motions and first control valve means for directing fluid to said stick cylinder for movement of said stick in digging motions, said system comprising hydraulic fluid delivery for supplying hydraulic fluid under pressure, first pilot operated valve means receiving fluid delivery means, a first conduit leading from said first pilot operated valve means to said first control valve means, said first pilot operated valve means being shiftable to a first condition responsive to the hydraulic pressure in said first conduit being below a predetermined amount when the digging motion of said stick is normal and being shiftable to a second condition responsive to hydraulic pressure in said first conduit being above a

Landscapes

  • Engineering & Computer Science (AREA)
  • Mining & Mineral Resources (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Paleontology (AREA)
  • Operation Control Of Excavators (AREA)
US831905A 1969-06-10 1969-06-10 Hydraulic control system for a backhoe Expired - Lifetime US3583585A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US83190569A 1969-06-10 1969-06-10

Publications (1)

Publication Number Publication Date
US3583585A true US3583585A (en) 1971-06-08

Family

ID=25260170

Family Applications (1)

Application Number Title Priority Date Filing Date
US831905A Expired - Lifetime US3583585A (en) 1969-06-10 1969-06-10 Hydraulic control system for a backhoe

Country Status (4)

Country Link
US (1) US3583585A (cs)
BE (1) BE744955A (cs)
FR (1) FR2052273A5 (cs)
LU (1) LU60353A1 (cs)

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3892079A (en) * 1971-12-27 1975-07-01 Hitachi Construction Machinery Control system for amphibious hydraulic excavator
US3901395A (en) * 1973-07-11 1975-08-26 Case Co J I Implement stabilization method and apparatus
US3905501A (en) * 1973-02-09 1975-09-16 Poclain Sa Control means for public works machine
US3960284A (en) * 1972-10-02 1976-06-01 American Hoist & Derrick Company Hydraulic backhoe circuitry
US3966065A (en) * 1974-08-19 1976-06-29 Hesston Corporation Safety hold-down apparatus for tractor-mounted earth working implements
US4218837A (en) * 1978-08-21 1980-08-26 Koehring Company High lift hydraulic system for an excavator
US4301607A (en) * 1979-04-18 1981-11-24 Kabushiki Kaisha Komatsu Seisakusho Hydraulic excavator
US4365429A (en) * 1981-11-18 1982-12-28 Bucyrus-Erie Company Maximum lift system for hydraulic hoe
US5446980A (en) * 1994-03-23 1995-09-05 Caterpillar Inc. Automatic excavation control system and method
US5461803A (en) * 1994-03-23 1995-10-31 Caterpillar Inc. System and method for determining the completion of a digging portion of an excavation work cycle
US5493798A (en) * 1994-06-15 1996-02-27 Caterpillar Inc. Teaching automatic excavation control system and method
US5528843A (en) * 1994-08-18 1996-06-25 Caterpillar Inc. Control system for automatically controlling a work implement of an earthworking machine to capture material
US5682312A (en) * 1994-03-23 1997-10-28 Caterpillar Inc. Self-adapting excavation control system and method
US6662556B2 (en) * 2001-11-15 2003-12-16 Clark Equipment Company Hydraulic systems for a small loader
US20040011427A1 (en) * 2002-07-19 2004-01-22 Liu William Pierre Hydraulic circuits for tree-harvesting knuckle booms
US6695567B2 (en) * 2000-02-28 2004-02-24 Kabushiki Kaisha Toyoda Jidoshokki Seisakusho Hydraulic device for industrial vehicles
US20040069375A1 (en) * 2002-09-16 2004-04-15 John Kurelek Hydraulic circuits for knuckle booms
US20050045245A1 (en) * 2003-08-26 2005-03-03 John Kurelek Knuckle boom for reaching and pulling and hydraulic circuits therefor
US20090056325A1 (en) * 2007-08-30 2009-03-05 Cochran Gary Hydraulic flow control system
US9297148B2 (en) 2013-07-24 2016-03-29 Deere And Company Intelligent boom control hydraulic system
US20230212839A1 (en) * 2021-02-22 2023-07-06 Komatsu Ltd. Method of estimating moment of work implement

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DD95205A5 (cs) * 1971-01-14 1973-01-12
FR2449812A1 (fr) * 1979-02-23 1980-09-19 Poclain Sa Ensemble de distribution de fluide comprenant plusieurs circuits distincts

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3339763A (en) * 1966-10-14 1967-09-05 Univ Oklahoma State Automatic back hoe control system
US3414146A (en) * 1966-08-11 1968-12-03 Ford Motor Co Automatic backhoe unit for use with industrial trucks and tractors

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3414146A (en) * 1966-08-11 1968-12-03 Ford Motor Co Automatic backhoe unit for use with industrial trucks and tractors
US3339763A (en) * 1966-10-14 1967-09-05 Univ Oklahoma State Automatic back hoe control system

Cited By (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3892079A (en) * 1971-12-27 1975-07-01 Hitachi Construction Machinery Control system for amphibious hydraulic excavator
US3960284A (en) * 1972-10-02 1976-06-01 American Hoist & Derrick Company Hydraulic backhoe circuitry
US3905501A (en) * 1973-02-09 1975-09-16 Poclain Sa Control means for public works machine
US3901395A (en) * 1973-07-11 1975-08-26 Case Co J I Implement stabilization method and apparatus
US3966065A (en) * 1974-08-19 1976-06-29 Hesston Corporation Safety hold-down apparatus for tractor-mounted earth working implements
US4218837A (en) * 1978-08-21 1980-08-26 Koehring Company High lift hydraulic system for an excavator
US4301607A (en) * 1979-04-18 1981-11-24 Kabushiki Kaisha Komatsu Seisakusho Hydraulic excavator
US4365429A (en) * 1981-11-18 1982-12-28 Bucyrus-Erie Company Maximum lift system for hydraulic hoe
US5682312A (en) * 1994-03-23 1997-10-28 Caterpillar Inc. Self-adapting excavation control system and method
US5446980A (en) * 1994-03-23 1995-09-05 Caterpillar Inc. Automatic excavation control system and method
US5461803A (en) * 1994-03-23 1995-10-31 Caterpillar Inc. System and method for determining the completion of a digging portion of an excavation work cycle
US5493798A (en) * 1994-06-15 1996-02-27 Caterpillar Inc. Teaching automatic excavation control system and method
US5528843A (en) * 1994-08-18 1996-06-25 Caterpillar Inc. Control system for automatically controlling a work implement of an earthworking machine to capture material
US6695567B2 (en) * 2000-02-28 2004-02-24 Kabushiki Kaisha Toyoda Jidoshokki Seisakusho Hydraulic device for industrial vehicles
US6662556B2 (en) * 2001-11-15 2003-12-16 Clark Equipment Company Hydraulic systems for a small loader
US6763863B2 (en) * 2002-07-19 2004-07-20 Tigercat Industries Inc. Hydraulic circuits for tree-harvesting knuckle booms
US20040011427A1 (en) * 2002-07-19 2004-01-22 Liu William Pierre Hydraulic circuits for tree-harvesting knuckle booms
US20040069375A1 (en) * 2002-09-16 2004-04-15 John Kurelek Hydraulic circuits for knuckle booms
US6997221B2 (en) * 2002-09-16 2006-02-14 Tigercat Industries Inc. Reach actuation for energy saving hydraulic knuckle booms
US20050045245A1 (en) * 2003-08-26 2005-03-03 John Kurelek Knuckle boom for reaching and pulling and hydraulic circuits therefor
US7007728B2 (en) * 2003-08-26 2006-03-07 Tigercat Industries Inc. Knuckle boom for reaching and pulling and hydraulic circuits therefor
US20090056325A1 (en) * 2007-08-30 2009-03-05 Cochran Gary Hydraulic flow control system
US8051651B2 (en) 2007-08-30 2011-11-08 Coneqtec Corp. Hydraulic flow control system
US9297148B2 (en) 2013-07-24 2016-03-29 Deere And Company Intelligent boom control hydraulic system
US20230212839A1 (en) * 2021-02-22 2023-07-06 Komatsu Ltd. Method of estimating moment of work implement
US12270183B2 (en) * 2021-02-22 2025-04-08 Komatsu Ltd. Method of estimating moment of work implement

Also Published As

Publication number Publication date
LU60353A1 (cs) 1970-04-16
BE744955A (fr) 1970-07-27
FR2052273A5 (cs) 1971-04-09

Similar Documents

Publication Publication Date Title
US3583585A (en) Hydraulic control system for a backhoe
US3563137A (en) Hydraulic self-leveling control for boom and bucket
US3339763A (en) Automatic back hoe control system
US3179120A (en) Proportional flow divider
JPH07504723A (ja) エネルギ回収装置
KR100228810B1 (ko) 건축기기용 유압장치
US6244048B1 (en) Hydraulique drive device
US2768499A (en) Hydraulic system comprising multiple pump and ram units
US1615055A (en) Hydraulic leveling and moving device
US3768372A (en) Control arrangement for hydraulic systems
US2988891A (en) Hydraulically responsive control system
US3938669A (en) Hydraulic circuit for a pipelayer
EP0436028B1 (en) Hydraulic circuit for operating cylinder of working machine
US3990583A (en) Device for controlling the boom elevation of a side crane
US3695474A (en) Hydraulic control linkage for implement
US3690387A (en) Boom rotation brake release means for derricks
US4344733A (en) Hydraulic control circuit for decelerating a swinging backhoe
US4126083A (en) Attitude control for implement
US3405823A (en) Hydraulic locking means for shiftable backhoe
US3905500A (en) Public works machine having a safety device for the manoeuvre of its working equipment
US3088489A (en) Detent release for flow control valves
US3122246A (en) Hydraulic circuit for tractor mounted loaders
US4218837A (en) High lift hydraulic system for an excavator
US3251277A (en) Fluid system and valve assembly therefor
US2879612A (en) Hydraulic drive for ditcher conveyor

Legal Events

Date Code Title Description
AS Assignment

Owner name: DANA CORPORATION A CORP OF VA

Free format text: MERGER;ASSIGNOR:TYRONE HYDRAULICS, INC. A DE CORP.;REEL/FRAME:004243/0378

Effective date: 19831221