WO2002022969A1 - Circuit hydraulique de vehicule servant a realiser des operations d'excavation et de pivotement - Google Patents
Circuit hydraulique de vehicule servant a realiser des operations d'excavation et de pivotement Download PDFInfo
- Publication number
- WO2002022969A1 WO2002022969A1 PCT/JP2001/007856 JP0107856W WO0222969A1 WO 2002022969 A1 WO2002022969 A1 WO 2002022969A1 JP 0107856 W JP0107856 W JP 0107856W WO 0222969 A1 WO0222969 A1 WO 0222969A1
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- WIPO (PCT)
- Prior art keywords
- hydraulic
- switching valve
- oil
- oil passage
- valve
- Prior art date
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Classifications
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- 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
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- 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
- E02F9/2285—Pilot-operated systems
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- 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
- E02F3/30—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 with a dipper-arm pivoted on a cantilever beam, i.e. boom
- E02F3/32—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 with a dipper-arm pivoted on a cantilever beam, i.e. boom working downwardly and towards the machine, e.g. with backhoes
- E02F3/325—Backhoes of the miniature type
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- 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
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- 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
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- 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
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- 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
- F15B2211/2053—Type of pump
- F15B2211/20538—Type of pump constant capacity
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- 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
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- 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
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- 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
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- 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
- F15B2211/40507—Flow control characterised by the type of flow control means or valve with constant throttles or orifices
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- 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
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- 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
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- 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
- F15B2211/635—Circuits providing pilot pressure to pilot pressure-controlled fluid circuit elements
- F15B2211/6355—Circuits providing pilot pressure to pilot pressure-controlled fluid circuit elements having valve means
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- 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
- F15B2211/705—Output members, e.g. hydraulic motors or cylinders or control therefor characterised by the type of output members or actuators
- F15B2211/7051—Linear output members
- F15B2211/7053—Double-acting output members
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- 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
- F15B2211/705—Output members, e.g. hydraulic motors or cylinders or control therefor characterised by the type of output members or actuators
- F15B2211/7058—Rotary output members
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- 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
- F15B2211/7114—Multiple output members, e.g. multiple hydraulic motors or cylinders with direct connection between the chambers of different actuators
- F15B2211/7128—Multiple output members, e.g. multiple hydraulic motors or cylinders with direct connection between the chambers of different actuators the chambers being connected in parallel
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- 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
- F15B2211/7135—Combinations of output members of different types, e.g. single-acting cylinders with rotary motors
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- 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
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- 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
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S37/00—Excavating
- Y10S37/902—Hydraulic motors
Definitions
- the present invention relates to a hydraulic excavator for driving a working part such as a boom, an arm, a bucket, and the like (a blade, etc.) of a small excavation and turning work vehicle, a hydraulic actuator for turning a main body, and a pair of right and left traveling.
- the hydraulic circuit is a two-pump hydraulic circuit that drives the hydraulic actuators and other hydraulic actuators efficiently, and ensures the traveling performance (especially the straightness) during other work sections during running and turning operations.
- the present invention relates to a device that ensures simultaneous operation of driving and turning of a working unit comparable to a three-pump system.
- a hydraulic cylinder for driving a boom, an arm, a bucket, a blade for discharging soil and a rocking boom bracket, a hydraulic motor for turning a main body, and a working machine of an excavating and turning work vehicle, and
- the pair of left and right traveling hydraulic motors are configured such that hydraulic oil is supplied and driven by a plurality of hydraulic pumps attached to the engine.
- three or more hydraulic pumps are provided.
- many hydraulic pumps are arranged in parallel in a small hood. It is common practice to arrange two hydraulic pumps because there is no such pump.
- Driving the actuator with three pumps is called the three-pump method
- driving the actuator with two pumps is called the two-pump method.
- Techniques for obtaining stable pressure oil by controlling the discharge pressure oil from the two hydraulic pumps include, for example, Japanese Patent No. 2760702 and Japanese Patent Application Laid-Open No. Hei 10-10-1.
- the technology of 0 5 9 3 3 is well known.
- one hydraulic pump drives the left traveling hydraulic motor, bucket cylinder, and boom cylinder, and the other hydraulic pump drives the right traveling hydraulic pressure.
- the motor, arm cylinder, and external hydraulic equipment are driven, and the oil passage is branched from the downstream side of the control valve of the traveling hydraulic motor to form a bypass oil passage, and a check valve is provided in the oil passage.
- valve is configured to be compact by stacking force directional switching valves that require three parallel oil passages, space is created to allow three common oil passages to pass through It is difficult.
- the technology disclosed in Japanese Patent Application Laid-Open No. H10-109593 is that if the excavation / turning work vehicle simultaneously operates the boom while traveling, a pressure difference occurs between the left and right traveling motors, and the vehicle cannot go straight. Therefore, the boom switching valve is connected to the downstream side of one of the left and right traveling switching valves in the evening, and the output side of the two hydraulic pumps is bypassed upstream of the left and right traveling switching valves. , And connected to the boom switching valve via the throttle from the bypass passage to compensate for pressure.
- the actuator that can keep the straightness even if it is operated at the same time during running is only for the boom, and when the actuators such as turning, arm, bucket and PTO are operated at the same time as running, Workability was not ensured, and they could also turn simultaneously, resulting in poor workability in the case of simultaneous work.
- the excavation work cycle consists of three stages: excavation, earth removal, return and positioning.
- the boom is first lowered, the tip of the bucket is brought into contact with the ground, and excavation is performed by simultaneously operating the arm and the bucket.
- excavation is performed by simultaneously operating the arm and the bucket.
- the work equipment provided above the equipment is swiveled, holding the bucket in the bucket and turning sideways, operating the bucket to discharge the soil.
- the working machine is returned to the original work position of the excavation and the positioning is performed.
- an arm and a bucket, a boom and a turn, an arm and a turn, or a boom and an arm and a turn are performed simultaneously.
- the schematic configuration of the supply of pressurized oil from the pump to the factory required for excavation work is as shown in Fig. 31 (a).
- the three pumps are configured to be able to supply pressurized oil to each of the three actuators, and as shown in Fig. 31 (b), the boom, arm and swivel described above are simultaneously operated. In operation, the simultaneous workability can be improved.
- the schematic configuration of the supply of pressurized oil from the pump to the factories required for excavation work is as shown in Fig. 32 (a).
- one pump power swivel and pressure oil is supplied to the arm, and the other pump is configured to supply pressure oil to the boom and baguette.
- an operation may be performed such that one pump drives two factories overnight.
- the two-pump system has some poor workability at the same time when a plurality of factories are operated at the same time. At present, it is only used for small aircraft. Disclosure of the invention
- the present invention relates to a hydraulic actuator (especially a hydraulic cylinder) for each working unit for driving a boom, an arm, a bucket, a swing, a blade, etc.
- Hydraulic pumps especially hydraulic motors
- the two hydraulic pumps are respectively provided with the two traveling hydraulic actuators.
- the object of the present invention is to provide the one with a pair of left and right running actuators for sure and uniform operability to improve straight running performance.
- each hydraulic pump backflow to each hydraulic pump is prevented by connecting the lower oil paths after branching the hydraulic oil supply path from each hydraulic pump to each traveling direction switching valve.
- a non-return valve to form a merging oil passage, and to the hydraulic oil suction port of the directional switching valve for each hydraulic actuator for the boom, bucket, swivel and arm for the merging oil passage,
- the hydraulic oil supply path via the throttle is branched and connected in parallel.
- the oil is first sent to the two traveling hydraulic motors and driven from the discharge oil passages of the two hydraulic pumps, prior to the other working units and the turning hydraulic work.
- the hydraulic oil supply and line for running are given priority, and the oil supply to other hydraulic actuators is performed by running hydraulic pressure.
- the hydraulic oil is supplied from the hydraulic oil supply path to the motor on the downstream side, and is sent from the junction oil path via a throttle, so that the operation of the other hydraulic actuators is suppressed. In this way, good running straightness can be ensured even when the vehicle is running during the driving of the hydraulic actuator other than the driving hydraulic actuator.
- the hydraulic oil supply passage is also branched via a throttle to the hydraulic oil suction port of the directional control valve for the hydraulic actuator for the blade.
- the branch point of the hydraulic oil supply passage to the blade directional switching valve in the merging oil passage is a branch point of the hydraulic oil supply passage to each traveling directional switching valve in the discharge oil passages of the two hydraulic pumps. It is located approximately in the middle between them.
- the pressure loss of the discharge oil from the two hydraulic pumps when they join at the junction point of the hydraulic oil supply path to the blade directional switching valve in the merged oil path becomes almost equal, and It is possible to improve the straight traveling when working with the blade (discharge work).
- the discharge oil passage of each of the hydraulic pumps is branched upstream of each of the check valves, and the boom, bucket, swivel, and arm direction switching valves pass through them in series when in a neutral state.
- a center-by / -oil passage that flows to the oil tank is formed, and the hydraulic oil suction port of each directional control valve is connected to the hydraulic oil from the primary bypass oil passage on the primary side of each directional control valve.
- the supply path is connected.
- one of the center bypass oil passages can pass through the boom directional switching valve and the bucket directional switching valve in series in this order.
- the center bypass oil passage and the merged oil passage In the center bypass oil passage and the merged oil passage
- the branch point of the hydraulic oil supply path to the boom directional control valve is located upstream of the branch point of the hydraulic oil supply path to the bucket directional control valve.
- one of the center bypass oil passages of the two center bypass oil passages can pass through the turning direction switching valve and the arm direction switching valve in series in order, and In the bypass oil passage and the merging oil passage, a branch point of the hydraulic oil supply path to the turning direction switching valve is located upstream of a branch point of the hydraulic oil supply path to the arm direction switching valve. ing.
- the hydraulic pressure of the second hydraulic pump can be supplied from the center bypass oil passage to the swing motor, which has a large inertia force and a large load during acceleration, without using a throttle. Since the hydraulic pressure of the first pump is supplied from the parallel circuit through the throttle, the swing and arm speed balance can be maintained.
- One of the two center bypass oil passages is a first center bypass oil passage and the other is a second center bypass oil passage, and the first center bypass oil passage is the boom directional switching valve and the bucket as described above.
- Hydraulic fluid is supplied from the first center bypass oil passage, and the turning direction switching valve and the arm direction are passed through the second center bypass oil passage as described above.
- a substantially independent circuit is constituted, and both of the simultaneous operation such as boom and swivel, bucket and swivel, arm and boom, and bucket and arm are performed. Actuyue can ensure the operability of the night.
- the most downstream end of the first center bypass oil passage is connected to the second center bypass oil passage on the primary side of the arm direction switching valve (between the turning direction switching valve).
- the pressure oil from the two hydraulic pumps is supplied to the arm directional control valve, and the combined pressure oil can increase the driving speed of the arm.
- a check valve is interposed at an upstream position of the most downstream end of the first center bypass oil passage, and further upstream thereof, the arm direction switching valve is further downstream than the first center bypass oil passage.
- the second center bypass oil passage is capable of passing through a directional switching valve for a PT0 driving actuator at a downstream side of the directional switching valve for the arm, and the directional switching valve for PT0 is connected to the merging port.
- the hydraulic oil supply path branched from the oil path is connected to the hydraulic oil suction port.
- the breaker rock drill
- the breaker requires a large flow of hydraulic oil, but the PTO directional control valve is supplied with hydraulic oil from the merged oil passage without passing through the The work can be performed by sending the hydraulic oil from both hydraulic pumps while minimizing the loss, and the work efficiency can be improved.
- the present invention aims at providing a hydraulic circuit configuration for maintaining a good operation balance when operating two or more hydraulic actuators as described above.
- the pump is driven by the discharge oil of one hydraulic pump and the swing and arm are driven by the discharge oil of the other hydraulic pump.This is not possible with a two-pump hydraulic circuit, but only with a three-pump type. It is an object of the present invention to enable the simultaneous operation of the arm and swivel and the simultaneous operation of the bucket, the arm and the swivel with a two-pump system, and to improve the operability.
- the present invention supplies the hydraulic oil discharged from the first hydraulic pump and the second hydraulic pump to each hydraulic actuator for the boom, bucket, swing, and arm via a separate directional switching valve.
- the boom directional switching valve is connected upstream in the discharge hydraulic passage of the first hydraulic pump, and the bucket directional switching valve is connected in tandem downstream.
- a turning direction switching valve and an arm direction switching valve are connected in tandem to the discharge oil passage, and the discharge oil passage from the first hydraulic pump is checked after passing through the bucket direction switching valve.
- a valve is connected to a portion between the turning direction switching valve and the arm direction switching valve in a discharge oil passage from the second hydraulic pump via a valve, and at a position upstream of the check valve.
- the discharge oil from the first hydraulic pump Branches more bleed circuit, the pre-time circuit, the directional control valve and ⁇ A for revolving - of the directional control valve for arm, and shall be opened and closed in conjunction with the switching of the directional control valve on the upstream side.
- a bridge circuit that opens and closes in conjunction with the upstream directional switching valve is provided.
- the bleed circuit is configured to switch the upstream directional switching valve between the turning directional switching valve and the arm directional switching valve. It is conceivable that the predirectional circuit is opened when the upstream directional control valve is in the neutral position and the bleed circuit is closed when the upstream directional control valve is in the operating position. In this case, improvement of the directional control valve on the upstream side can provide the on-off valve structure without providing a valve member for opening and closing the bleed circuit, so that a space for new component arrangement can be provided. It is not necessary to provide.
- a throttle is formed in the bleed circuit in the directional control valve on the upstream side configured as described above. Therefore, among the hydraulic actuators for turning and arm, those whose directional control valves are arranged on the downstream side, bleed out the discharge oil from the first hydraulic pump during independent operation. While adjusting the pressure, it can be combined with the discharge oil from the second hydraulic pump and supplied to the factory.
- this throttle By incorporating this throttle into a spool for opening and closing the bleed circuit in the directional control valve, it is possible to provide a throttle that can adjust the amount of the bridge at a low cost with a simple structure. However, when it is desired to change the opening, it is possible to easily change the opening simply by replacing the spool and adjust the driving speed of the hydraulic actuator.
- the bleed switching valve interlocked with the upstream direction switching valve of the turning direction switching valve and the arm direction switching valve is provided in the preed circuit. It may be interposed.
- the improvement of the directional control valve was not required, and the addition of the bleed switch valve and the interlocking and linking structure between the bleed switch valve and the upstream directional switch valve made it impossible with the conventional two-pump type described above. Simultaneous turning and cam operation are possible.
- the directional switching valve is arranged downstream of the hydraulic actuator for turning and arm.
- the oil discharged from the first hydraulic pump is combined with the oil discharged from the second hydraulic pump while bleeding and adjusting the amount during independent driving. And the operating speed of the hydraulic actuator can be increased.
- the upstream directional switching valve and the bleed switching valve are hydraulic pilot type switching valves, and the upstream directional switching valve is provided.
- a pilot oil passage connecting a pilot operating valve for controlling a hydraulic pilot of the valve and a pilot operating part of the upstream direction switching valve is branched, and a pilot operation of the bridge switching valve is performed. It is conceivable to connect to the unit. Thereby, the interlocking linkage between the two switching valves can be reliably performed.
- a high pressure selection valve is provided in a pilot oil passage connecting the pilot operation valve and the upstream direction switching valve, and a pilot oil passage to the bleed switching valve is branched from the high pressure selection valve.
- the bleed switching valve always passes through the oil passage from the T port of the directional switching valve on the downstream side of the turning direction switching valve and the arm direction switching valve. Hydraulic oil can be supplied to the PTO direction switching valve from the lower side of the reed switching valve. As a result, during the PTO drive, by setting the other hydraulic actuators to a neutral state, the hydraulic oil from the first hydraulic pump and the second hydraulic pump can be combined and supplied to PT 0, The operability of the 0-drive working machine can be improved.
- the P port and the T port which are communicated with each other when in the neutral position, are configured to communicate with each other through the throttle when in the operating position, so that the boom is operated when the boom is operated.
- the discharge oil from the first hydraulic pump flows downstream thereof and can be combined with the discharge oil from the second hydraulic pump.
- the hydraulic oil from the first hydraulic pump also flows to the direction switching valve located on the downstream side of the turning direction switching valve and the arm direction switching valve. Therefore, in the same manner as the three-pump system, it is possible to simultaneously perform the two operations of the arm and the boom and the three operations of the swiveling of the revolving unit, even in the two-pump system.
- the direction switching on the upstream side of the turning direction switching valve and the arm direction switching valve is performed.
- the P port and the T port that communicate with each other when in the neutral position
- the upstream directional control valve When in the operating position, it may be connected through a throttle. According to this, when the upstream directional control valve is in the operating position, a part of the hydraulic oil from the second hydraulic pump also flows to the downstream directional control valve, so that the boom (or bucket) can be removed. Even when the discharge oil from the first hydraulic pump does not reach the discharge oil passage from the second hydraulic pump by driving, the discharge oil from the second hydraulic pump is supplied to the direction switching valve on the downstream side. Therefore, in the same way as the three-bump type hydraulic circuit, it is possible to simultaneously perform the three operations of the arm and boom drive and the revolving body swivel, as in the three-bump type hydraulic circuit.
- the above-described three-way operation can be performed simultaneously.
- the operation of the three hydraulic factories during the operation is equalized, and good simultaneous operation can be provided.
- FIG. 1 is an overall side view of a digging and turning work vehicle having a two-pump hydraulic circuit according to the present invention
- FIG. 2 shows a general digging cycle and movement of each part by the digging and turning work vehicle.
- FIG. 3 is a schematic diagram.
- FIG. 3 shows a hydraulic oil supply circuit for a boom cylinder 23, an arm cylinder 29, a bucket cylinder 24, and a swing motor 13 in a basic two-pump hydraulic circuit according to the present invention.
- (A) shows a schematic diagram consisting of two basic independent circuits
- (b) shows a schematic diagram of a hydraulic circuit in which hydraulic oil can be merged or exchanged between the two independent circuits.
- FIG. 4 shows a circuit provided with a single circuit (particularly, the hydraulic circuit 101 shown in FIG. 10).
- FIG. 4 shows a boom, bucket, arm, turning Hydraulic circuit for excavation work vehicle with a structure that gives priority to driving
- FIG. 5 is an enlarged circuit diagram of a first pump side portion of the hydraulic circuit 100
- FIG. 6 is an enlarged circuit diagram of a central portion of the hydraulic circuit 100
- Fig. 7 shows the second hydraulic pump side portion of the hydraulic circuit 100
- FIG. 8 is an example of a modification of the hydraulic circuit 100.
- FIG. 8 is a circuit diagram of a hydraulic circuit 100a in which a bleed circuit for adjusting the arm speed is configured as a turning direction switching valve 54.
- Fig. 9 is a circuit diagram of a hydraulic circuit 10 Ob, which is also a modified example thereof.
- FIG. 10 is an excavation of a structure that enables simultaneous turning and arm driving according to the present invention.
- FIG. 11 is a diagram showing a state in which an omnidirectional switching valve is set to a neutral position in a hydraulic circuit 101 of the turning work vehicle.
- FIG. 11 shows an operation position of an arm directional switching valve 55 in the hydraulic circuit 101.
- FIG. 12 is a view showing a state in which the turning direction switching valve 54 is set to the operating position in the hydraulic circuit 101
- FIG. 13 is a view showing the hydraulic pressure
- FIG. 14 is a diagram showing a state in which the arm directional switching valve 55 and the turning directional switching valve 54 are in the operating position in the circuit 101, and FIG. FIG.
- FIG. 15 is a diagram showing a state in which the directional switching valve for the bucket, the directional switching valve for the arm 55, and the directional switching valve for turning 54 are set to the operating positions in the hydraulic circuit 101
- FIG. FIG. 16 is a diagram showing a state in which the PTO directional switching valve is set to an operating position in the hydraulic circuit 101
- FIG. 16 is a diagram showing driving of the arm 5, the baguette 4, and the boom 6 by the hydraulic circuit 100.
- FIG. 17 is a diagram showing the suitability of simultaneous operability in turning the revolving unit 8 and FIG. 17 is a hydraulic circuit 101 a having a structure in which a bleed throttle 54 a is provided in the turning direction switching valve 54.
- FIG. 18 is a view showing a state in which the omnidirectional switching valve is set to a neutral position in FIG. 18.
- FIG. 18 is a diagram illustrating a bucket directional switching valve, a boom directional switching valve 51, and an arm direction in the hydraulic circuit 101a.
- FIG. 19 is a diagram showing a state in which the switching valve 55 and the turning direction switching valve 54 are in the operating position.
- FIG. 19 shows the hydraulic circuit 101 a
- Fig. 20 is a list showing the suitability of simultaneous operability in driving the arm 5, baguette 4, boom 6 and swiveling of the revolving unit 8 according to Fig. 20.
- the directional control valve for the bucket is provided with a bleed throttle 51a.
- FIG. 21 is a diagram showing a state in which the omnidirectional switching valve is set to a neutral position in the hydraulic circuit 101 b having a bent structure
- FIG. 21 is a diagram illustrating a boom directional switching valve 51 and an arm for the hydraulic circuit 101 b.
- FIG. 22 is a view showing a state in which the directional control valve 55 and the turning directional control valve 54 are set to the operating position
- FIG. 22 is a diagram showing the operation of the hydraulic circuit 10 lb for driving the arm 5, the knocket 4, and the boom 6
- FIG. 23 is a list showing the suitability of the simultaneous operation during the turning of the revolving unit 8, and FIG.
- FIG. 23 is a hydraulic circuit 1 having a structure in which a bleed throttle is provided in both the bucket direction switching valve and the swing direction switching valve 54.
- FIG. 11 is a diagram showing a state where the omnidirectional switching valve is set to a neutral position at 0 1 c 2 4 figures blanking in the hydraulic circuit 1 0 1 c
- FIG. 25 is a view showing a state in which the arm direction switching valve 51, the arm direction switching valve 55, and the turning direction switching valve 54 are in the operating position.
- FIG. FIG. 26 is a list showing the suitability of simultaneous operability in driving the arm 5, the baguette 4, the boom 6, and turning the revolving unit 8, and FIG. 26 shows a structure in which a throttle 75 is formed in the bleed switching valve 85.
- FIG. 11 is a diagram showing a state where the omnidirectional switching valve is set to a neutral position at 0 1 c 2 4 figures blanking in the hydraulic circuit 1 0 1 c
- FIG. 25 is a view showing a state in
- FIG. 27 is a view showing a state in which the omnidirectional switching valve is in the neutral position in the hydraulic circuit 101 d of FIG. 27.
- FIG. 27 is a diagram showing the operation position of the arm directional switching valve 55 in the hydraulic circuit 101 d.
- FIG. 28 is a diagram of a hydraulic circuit 101 e having a structure in which the turning direction switching valve 54 and the arm direction switching valve 55 are interchanged.
- Fig. 9 shows the directional switching valve 55 for the arm, the directional switching valve for the bucket, the directional switching valve 54 for the swing, the directional switching valve 55 for the arm, and the bleed switching valve.
- FIG. 9 shows the directional switching valve 55 for the arm, the directional switching valve for the bucket, the directional switching valve 54 for the swing, the directional switching valve 55 for the arm, and the bleed switching valve.
- FIG. 8 is a diagram of a hydraulic circuit 101 f having a structure in which a directional switching valve 54 for turning and a bleed switching valve receive a hydraulic pilot from the same pilot operating valve as a pressure pilot type control valve.
- FIG. 30 is a diagram of a hydraulic circuit 101 g having a structure in which a bleed switching valve receives a hydraulic pilot from a high-pressure selection valve, and
- FIG. 31 shows a conventional three-pump system.
- Fig. 32 is a conceptual diagram of the hydraulic circuit and a diagram showing the suitability of simultaneous operation.
- Fig. 32 is a conceptual diagram of a conventional two-pump type hydraulic circuit and a diagram showing the suitability of simultaneous operation. BEST MODE FOR CARRYING OUT THE INVENTION
- the turning work vehicle supports a revolving body 8 so as to be able to turn via a turning table bearing 7 having a vertical axis at the center of the upper part of the crawler traveling device 1.
- a blade 10 for discharging the earth is vertically rotatably supported.
- a bonnet 9 for covering an engine or the like is provided above the revolving superstructure 2, and a seat 22 is attached above the bonnet 9.
- levers for performing a driving operation and the like are arranged on the front column 19.
- a floor plate portion 20 is disposed between the front column 19 and the hood 9.
- a boom bracket 12 is attached to the front end of the revolving unit 8 so as to be rotatable left and right.
- the lower end of the boom 6 is supported by the boom bracket 12 so as to be rotatable back and forth.
- the boom 6 is bent forward in the middle, and is formed in a substantially “C” shape in side view.
- An arm 5 is rotatably supported at an upper end of the boom 6, and a bucket 4 as a work attachment is rotatably supported at a tip of the arm 5.
- a hydraulic working machine such as a breaker (rock drill) can be mounted in place of the bucket 4, and when this breaker is mounted, pressurized oil is supplied from a PTO port described later.
- the working machine 2 is constituted by the boom 6, the arm 5, the bucket 4, and the like.
- the boom 6 is rotated by a boom cylinder 23, the arm 5 is rotated by an arm cylinder 29, and the baguette 4 is rotated by a baguette cylinder 24.
- the cylinder 23, the arm cylinder 29, and the baguette cylinder 24 are composed of hydraulic cylinders, and each cylinder 23, 29, 24 is disposed in the bonnet 9 of the revolving unit 8 as described later.
- the hydraulic pump is driven to expand and contract by supplying pressure oil through a directional switching valve and a hydraulic hose.
- the boom cylinder 23 is interposed between the boom bracket 12 and the boom cylinder bracket 25 provided on the front of the middle of the boom 6, and the arm cylinder 29 is mounted on the back of the middle of the boom 6. It is interposed between the provided arm cylinder bottom bracket 26 and the bucket cylinder placket 27 provided at the base end of the arm 5, and the baggage cylinder 2 is connected to the bucket cylinder placket 27 and the baguette 4. It is interposed between the station and 11.
- a swing cylinder 17 is arranged on the lower side of the revolving structure 8, and the base is pivotally supported by the revolving frame.
- the tip of the cylinder rod of the swing cylinder 17 is connected to the bracket 12.
- the swing cylinder 17 allows the bracket 12 to rotate left and right with respect to the revolving unit 8, thereby enabling the work machine 2 to rotate left and right.
- the revolving unit 8 can be rotated left and right by 360 degrees by the operation of a hydraulic hydraulic motor 13 provided on the upper part of the revolving base bearing 7, and the blade 10 is a track of the crawler type traveling device 1. It can be moved up and down by the operation of the blade cylinder 14 extended from the frame 3. Furthermore, the left and right disposed on one side of the front and rear of the track frame 3 Left and right traveling hydraulic motors 15 R-15 L are arranged inside the driving sprockets 16 ⁇ 16 of the vehicle, respectively, so that the crawler traveling device 1 can be driven to travel.
- These hydraulic cylinders and hydraulic motors which are hydraulic actuators, can be driven by operating levers and pedals provided on the front column 19 and the step 20. Alternatively, automatic control is also possible.
- the excavation work cycle consists of three stages: excavation, dumping, return and positioning.
- the boom 6 is lowered, the tip of the bucket 4 is brought into contact with the ground, and the arm 5 and the bucket 4 are simultaneously operated to perform excavation.
- the horse motion of the boom 6 and the turning of the work machine body (the revolving unit 8) provided above the crawler-type traveling device 1 are simultaneously performed, and the vehicle is turned sideways while holding the soil in the bucket 4.
- the arm 5 and the swing are operated at the same time, or the boom 6, the arm 5 and the swing are operated at the same time to return the working machine to the original work position of the excavation and position the work machine.
- the arm 5 and the bucket 4 the boom 6 and the swing (drive of the swing body 8), the arm 5 and the swing, or the boom 6 and the arm 5 and the swing Simultaneous operations are performed.
- the problem of the various embodiments of the hydraulic circuit disclosed below is that, first of all, of the simultaneous operations required for these excavation operations, at least two of the working units must be ensured simultaneously. That is to be able to do it.
- the entire hydraulic circuit described below is used to drive the boom cylinder 23, the bucket cylinder 24, the arm cylinder 29, and the swing motor 13, which are the basic hydraulic functions of the excavation work vehicle.
- the first hydraulic pump P1 supplies hydraulic oil to the boom cylinder 23 and the baguette cylinder 24, and the second hydraulic pump P2 supplies Hydraulic oil is to be supplied to the arm cylinder 29 and the swing motor 13. That is, the hydraulic pump supply destination of the hydraulic oil is specified for the two hydraulic pumps P 1 and P 2. In other words, each hydraulic pump forms an independent circuit.
- each of the pumps P 1 and P 2 is supplied with hydraulic oil substantially independently, so that the respective driving forces can be secured, that is, the simultaneous operability of the hydraulic actuators can be secured.
- FIG. 3 (b) particularly shows a pre-switching valve 85 and a check valve 68 provided in the hydraulic circuit 101 shown in FIGS. 10 to 13 described later.
- FIG. 5 is a schematic diagram showing a case where hydraulic oil is supplied from the first hydraulic pump P1 to the arm cylinder 29 by using a hydraulic circuit.
- FIG. 8 shows two embodiments of the hydraulic circuit 101 shown in FIGS. 0 to 16, and FIG. 9 shows a hydraulic circuit 100a and a hydraulic circuit 100a shown in FIG.
- the first hydraulic pump P1 and the second hydraulic pump P2 are driven by the engine housed in the bonnet 9. And, as shown in FIG. 4, a tank oil passage 34 constantly connected to the oil tank is formed, and between the output (discharge) oil passage of the first hydraulic pump P 1 and the tank oil passage 34.
- the relief valve 61 force is also interposed between the output (discharge) oil passage of the second hydraulic pump P 2 and the tank oil passage 34, and each hydraulic pump P 1 ⁇
- the discharge hydraulic pressure of P2 is to be adjusted.
- the hydraulic oil (for the optional mounting actuator) of the optional directional control valve 57 is provided. It branches into a hydraulic oil supply oil passage connected to the suction port, a first center bypass oil passage 31, and a branch oil passage 33 a of the parallel oil passage 33.
- the first center bypass oil passage 31 is provided with an optional directional switching valve 57, a swing directional switching valve 58, and one of the left and right traveling motors (in this embodiment, the right traveling motor 1 5 R)
- all these directional control valves are in the neutral position.
- the first center bypass oil passage 31 is connected to the second hydraulic pump-side center bypass oil passage 32, as described later.
- the oil discharged from the first hydraulic pump P1 after passing through the directional control valve 53 is joined to the second hydraulic pump-side center bypass oil passage 32.
- the discharge oil passage of the second hydraulic pump P2 is branched to the relief valve 61, and then the direction switching valve 50 for the other left and right traveling motor (in this embodiment, for the left traveling motor 15L) is opened.
- the second hydraulic pump side center bypass oil passage 32 is provided with a left traveling motor direction switching valve 50 L, a turning direction switching valve 54, an arm direction switching valve 55, and a PTO direction switching valve. 5 and 6 are connected in series (tandem arrangement). When all of these directional control valves are in the neutral position, they are all opened and oil from the second hydraulic pump P 1 is discharged. These directional control valves 50 L ⁇ 54, 55, and 56 are all passed through and drained to the tank oil passage 34.
- the most downstream end of the first center bypass oil passage 31 (downstream of the blade directional switching valve 53) is connected to the second center bypass oil passage 31 via a check valve 68.
- a portion of the hydraulic pump side bypass oil passage 32 between the turning direction switching valve 54 and the arm direction switching valve 55 (that is, the upstream side of the arm direction switching valve 55) (neutral connection portion) ) Connected to 5-9. Therefore, when the omnidirectional directional control valve is neutral, the first hydraulic pressure is actually applied to the second center bypass oil passage 32 passing through the directional control valve 55 and the PTO directional control valve 56. The combined oil of the pump P1 and the second hydraulic pump P2 will pass.
- the parallel oil passage 3 3 is composed of a branch oil passage 3 3a ⁇ 3 3b and a junction oil passage 3 3c.
- the branch oil passage 3 3a branched from the discharge oil passage of the first hydraulic pump P 1 and a junction oil passage.
- a check valve (check valve) 40 is arranged between 33 c and between the branch oil passage 33 b and the junction oil passage 33 c branched from the discharge oil passage of the second hydraulic pump P 2. Is provided with a check valve 41. That is, the joining oil passage 33c is interposed between the check valves 40 and 41 for preventing the backflow with the first hydraulic pump P1 and the second hydraulic pump P2.
- Each directional control valve supplies the hydraulic oil of each hydraulic actuator in parallel from one of the branch oil passages 33a and 33b of the parallel oil passage 33 and the merge oil passage 33c. It is supplied.
- Each directional control valve 5 OR * 50 L5 1 5 2 5 3 5 4 5 5 5 6 5 7 Each can be switched by operating a lever or pedal on the revolving superstructure 8. Instead of such manual operation, it is conceivable to use a directional switching valve as a pilot operation valve and automatically control the actuator.
- each directional control valve Of the remaining four ports of each directional control valve, one is either the branch oil path 33a, 33b (or its upstream end) of the parallel oil path 33, or the junction oil path 33c, as described above. It is connected to the port to provide a hydraulic oil intake port for the factory. One is connected to the tank oil passage 34 to serve as a hydraulic oil discharge port for actuators.
- each hydraulic actuator is connected to each hydraulic actuator. That is, among the hydraulic actuators, the hydraulic cylinder is a double-acting cylinder, the hydraulic motor is a forward / reverse motor, and is operated in two opposite directions. , One of two operating positions other than the neutral position One of the two ports of each directional control valve is set to the suction side, and either of them is set to the discharge side, and hydraulic fluid is supplied from each directional control valve to each actuator to obtain the two-way valve. It works in one of the directions.
- the optional directional control valve 57 is provided with an optional hydraulic device, such as a hydraulic cylinder for adjusting the width of a crawler, via an oil passage 90a and 90b. Pressure oil can be supplied.
- an optional hydraulic device such as a hydraulic cylinder for adjusting the width of a crawler
- the swing direction switching valve 58 is connected to the swing cylinder 17 via oil passages 91a and 91b, and the right traveling direction switching valve 50R is connected to the oil passages 92a and 92b. Through the right hydraulic motor 15R.
- the boom directional control valve 51 is connected to the boom cylinder 23 via oil passages 93a and 93b.
- the oil passage 93b is connected to the tank oil from the hydraulic oil discharge port of the boom directional switching valve 51 via a parallel overload relief valve 62 and a check valve 80.
- the hydraulic oil discharge oil passage to the passage 34 is also connected to the hydraulic oil discharge oil passage (hereinafter, the oil passage connected from each directional control valve to the tank oil passage 34 is referred to as “the hydraulic oil discharge oil passage”). When an overload is applied, the hydraulic oil can be re-released to the oil passage 34 from the over-the-mouth relief valve 62.
- the bucket directional switching valve 52 is connected to the bucket cylinder 24 via oil passages 94a and 94b, and the blade directional switching valve 53 is connected to the oil passage 9 It is connected to the blade cylinder 14 via 5a • 95b.
- the left traveling direction switching valve 50L is connected to the left traveling hydraulic motor 15L via oil passages 99a and 99b.
- the turning direction switching valve 54 is connected to the turning hydraulic motor 13 via oil passages 98a and 89b.
- the oil passage 98a is connected to a parallel overload relief valve 64 and a check valve 82
- the oil passage 98b is connected to a parallel overload relief valve 65 and a check valve.
- 8 and 3 respectively, are connected to the hydraulic oil discharge oil passage of the turning direction switching valve 54, and when the revolving unit 8 is turned right or left, an overload is applied to the tank oil. Roads 3 and 4 can be relieved of hydraulic oil.
- the arm direction switching valve 55 is connected to the arm cylinder 29 via oil passages 97a and 97b.
- the oil passage 97 b communicates with the hydraulic oil discharge oil passage of the directional control valve 55 for the arm via a parallel overload relief valve 63 and a check valve 81 to prevent overload.
- the hydraulic oil can be relieved from the over-open relief valve 63 when it is applied.
- the directional control valve 50 L for the left traveling motor is connected to the branch oil passage 3 3 b in the discharge oil passage of the second hydraulic pump P 2 as shown in FIGS. 4 and 7.
- the hydraulic oil supply oil passage is connected from the upstream end of (the upstream side of the check valve 41).
- the hydraulic oil supply oil passage to the boom directional switching valve 51 is provided with a tandem throttle 70 and a check valve 46, and a bucket directional switching valve.
- a throttle 71 and a check valve 47 are provided in tandem in the hydraulic oil supply oil passage to valve 52, and a throttle 72 is provided in the hydraulic oil supply oil passage to blade directional switching valve 53, turning In the hydraulic oil supply oil passage to the directional control valve 54, a tandem throttle 73 and a check valve 48 are provided.
- a tandem throttle ⁇ 4 and a check valve 49 are provided in the hydraulic oil supply oil passage to the directional control valve 55, and a check valve 69 is provided in the hydraulic oil supply oil passage to the PTO directional change valve 56. , Respectively.
- each of these check valves is to prevent a backflow to the junction oil passage 33c.
- the downstream side of the check valve 46 of the hydraulic oil supply oil passage from the branch oil passage 33 c to the boom direction switching valve 51 is connected to the boom direction by way of a check valve 42. It is connected to the first pump-side bypass oil passage 31 on the upstream side of the switching valve 51 (between the right-direction directional switching valve 5OR), and similarly to the bucket directional switching valve 52.
- the non-return valve 47 of the hydraulic oil supply oil passage communicates with the first pump side bypass oil passage 31 via the check valve 43 via the check valve 43, and supplies hydraulic oil to the turning direction switching valve 54.
- the non-return valve of the oil passage check valve 4 8 passes through the check valve 4 4 and the check valve of the hydraulic oil supply oil passage to the directional control valve 5 5 for the arm.
- the downstream side 49 communicates with the second hydraulic pump side bypass oil passage 32 through the check valve 45, respectively.
- the check valve 45 is connected to the neutral connection portion of the second hydraulic pump-side bypass oil passage 32 that joins the most downstream end of the first pump-side bypass oil passage 31 described above.
- check valves 4 2, 4 3, 4 4, 4 5 allow only the flow from each center bypass oil passage 3 1, 3 2 to each hydraulic oil supply oil passage, and each center bypass oil passage 3 Enables supply of hydraulic oil to each directional control valve from 1-3 2.
- Hydraulic oil to the swing direction switching valve 58 should be upstream of the hydraulic oil supply oil path to the right traveling motor direction switching valve 5 OR in the branch oil passage 33a from the first hydraulic pump P1.
- the swing cylinder 17 does not receive a large load during its operation. Therefore, even if the hydraulic oil is supplied in this manner, the right-hand and left-hand directional changeover valve 5 OR, There is no hindrance to the supply of hydraulic oil from the junction oil passage 33 to each directional control valve. The same is true for the option-installed hydraulic actuator.
- the directional control valves 50 R and 50 L for both traveling motors are supplied with hydraulic oil from the branch oil passages 33 a and 33 b upstream of the merged oil passage 33 c, respectively.
- the directional control valves 50 R and 50 L for both traveling motors were set to one of the two operating positions, respectively.
- “to be in the operating position” means, as described above, to be in one of the two operating positions.
- 3 2 is shut off at each traveling directional switching valve 50 L, 50 R, and the downstream directional switching valve 5 1-5 2-5 in each sensor bypass oil passage 3 1, 3 2 Three
- hydraulic oil can be supplied via the converging oil passage 33c via a restrictor 70, 71, 72, 73, 74.
- the boom 6, the arm 5, the blade 10 or L ⁇ are used to drive the respective working units of the baguette 4, or to turn the revolving body 8, these direction switching valves are used.
- the directional control valve 5 OR The hydraulic oil is supplied from each of the hydraulic pumps P 1 and P 2 upstream of the hydraulic oil supply oil passage to the directional control valves 51 to 55, and the work is performed by the action of each throttle.
- the oil supply to the hydraulic drive for the drive unit and revolving structure 8 is restricted.
- the amount of pressurized oil from the two hydraulic pumps P 1 and P 2 to the traveling oil pressure motors 15 R and 15 L is secured, and straightness can be maintained.
- the traveling drive is prioritized over the other working unit, and the straightness is ensured.
- Hydraulic oil for the factory is supplied from 1. Also, a directional control valve for the left traveling motor
- the boom cylinder 23 and the bucket cylinder 24 are connected to the first hydraulic pump. From P1, the swing motor 13 and the arm cylinder 2 9 power ⁇ The second hydraulic pump P2 power, etc., are supplied with hydraulic oil respectively.
- the directional control valves 5 1-5-5 4 ⁇ 5 5 are also connected to the junction oil passage 3 3 c through the throttle to be used for each actuator. Hydraulic fluid is supplied. Therefore, for example, when the boom 6 is driven independently, the discharge oil of the first hydraulic pump P1 is directly supplied from the first hydraulic pump bypass passage 31 and the combined hydraulic passage 33c is provided.
- the driving force is driven only by the hydraulic oil from the first hydraulic pump P1. It is higher than when it is done.
- the boom cylinder 23, the bucket cylinder 24, the swing motor 13 and the arm cylinder 29 are supplied with the discharge oil of each original hydraulic pump, and are also captured from the other hydraulic pump. Since hydraulic oil is supplied temporarily, the operating speed is increased and working efficiency is improved.
- the arm directional switching valve 55 is a neutral portion that is a junction between the first center bypass oil passage 31 and the second center bypass oil passage 32 formed between the turning directional switching valve 54 and the turning directional switching valve 54. Hydraulic oil can be supplied from the connection 59 through the check valve 45. Therefore, when only the arm 5 is operated, the hydraulic oil is supplied from the neutral connection portion 59 where the pressure oils from both the pumps p 1 and p 2 join without passing through the throttle, and the force of the joint oil passage 3 Since hydraulic fluid is supplied via the throttle 74, the arm 5 can be driven quickly, with a larger driving force being secured to the arm cylinder 29.
- the bleed oil passage 35 from the first center bypass oil passage 31 is connected to the lower side of the second center bypass oil passage 3 2 of the arm directional switching valve 55 via the throttle 75.
- the bridge oil passage 35 is located on the more upstream side than the neutral connection portion 59 as the first center bypass oil passage 31, so that the first center Pressure oil flows from the bypass oil passage 3 1 to the second center bypass oil passage 3 2 Therefore, the amount of pressurized oil from the first center bypass oil passage 31 that joins the neutral connection portion 59 is limited.
- the combined pressure oil amount of the two center bypass oil passages 3 1 and 3 2 supplied to the hydraulic oil suction port of the arm directional switching valve 55 is limited, and the operation speed of the arm cylinder 29 is limited. Has been adjusted.
- Each directional control valve shuts off the center bypass oil passage 31 or 32 when it is set to the operating position. Therefore, the direction in which the tandem is disposed downstream along the center bypass oil passages 31 and 32 The switching valve is no longer supplied or passed with hydraulic oil from the center bypass oil passages 31 and 32, and can receive hydraulic oil only from the parallel oil passage 33.
- This configuration contributes to the operation balance when a plurality of actuators that should receive the hydraulic oil from the same hydraulic pump (that is, one actuator in the same independent circuit) are simultaneously operated.
- the hydraulic oil suction port of the boom directional switching valve 51 is connected upstream of the hydraulic oil suction port of the bucket directional switching valve 52.
- the directional control valve 51 for the boom which is in the operating position, is directly connected to the first center bypass oil passage 31 without passing through the throttle.
- Hydraulic oil is supplied, and hydraulic oil is also supplied from the merging oil passage 33c via the throttle 70, so that a large driving force can be obtained for the boom cylinder 23, while the bucket in the operating position Hydraulic oil is not supplied from the first pump-side bypass oil passage 31 shut off by the boom directional change valve 51, and the throttle 71 Bucket cylinder 2 The driving force of 4 is suppressed.
- the boom 6 has a larger mass and a greater load than the baguette 4, so the hydraulic pressure required to operate the boom cylinder 23 and the bucket cylinder 24 is also lower than the boom cylinder 2. 3 is larger than baguette cylinder 24. Therefore, by supplying the hydraulic oil to the two-way switching valves 51 and 52 as described above, the hydraulic pressure during operation can be balanced, and the operating speeds of both can be balanced, so that work can be performed smoothly without feeling uncomfortable. You can do it.
- the hydraulic fluid of the turning direction switching valve 54 is sucked into the second center bypass oil passage 32.
- the input port is connected upstream of the hydraulic oil suction port of the directional control valve 55 for the arm, so if the swing hydraulic motor 13 and the arm cylinder 29 are to be operated at the same time, the operating position
- the hydraulic directional switching valve 54 is supplied with hydraulic oil directly from the center bypass oil passage 32 on the second hydraulic pump side without passing through a throttle, and is also supplied via a throttle 73 from the merging oil passage 33 c. Since hydraulic oil is supplied to the swing hydraulic motor 13, a large driving force can be obtained.
- hydraulic fluid is not supplied to the arm directional switching valve 55 in the operating position from the second center bypass oil passage 32 which is shut off by the turning hydraulic motor 13, but the neutral connection portion 5 9
- Pressure oil from the first center bypass oil passage 31 introduced into the arm cylinder 29 is supplied as hydraulic oil for the arm cylinder 29.
- Hydraulic oil is supplied from the first oil bypass oil passage 31 via the throttle 74 from the force joining oil passage 33 c, which is reduced by the amount that has escaped to the pre-oil passage 35.
- the driving force of the arm cylinder 29 can be secured.
- the amount of hydraulic oil is reduced.
- the revolving unit 8 has a larger mass than the arm 5 and a large load due to a large inertial force, but as described above, the hydraulic pressure for operating the swing hydraulic motor 13 and the arm cylinder 29 is reduced.
- the turning hydraulic motor is designed so that it is larger than it is 13 times, so the hydraulic pressure during operation can be balanced and the operating speeds of both can be balanced, so that work can be performed smoothly without any discomfort It is.
- the hydraulic circuit 1 When the driving of the arm 5 and the driving of the swing body 8 are performed simultaneously, the hydraulic circuit 1 In some cases, as described above, the pressure oil is supplied to the arm cylinder 24 and the swing motor 13 separately from the first hydraulic pump P1 and the second hydraulic pump P2, respectively. The Rukoto. However, the working oil pressure to the arm cylinder 24 is limited by the bleed oil passage 35. If it is not necessary to suppress the operating force of the arm cylinder 24 during turning, and it is desired to further increase the operating speed of the arm 5 during turning, the hydraulic circuit 10 shown in FIGS. 8 and 9 described later is used. 0 a ⁇ 100 b may be used. When the turning direction switching valve 54 is set to the operating position, the pressure oil from the first center bypass oil passage 31 is supplied to the arm direction switching valve 55 without being fed. This improves the operability of the arm 5 during turning.
- the PTO directional control valve 56 does not supply hydraulic oil to the hydraulic oil suction port from the second center bypass oil passage 32, the hydraulic oil supply oil passage from It is connected to the hydraulic oil suction port without intervening (via the check valve 69), so that a high hydraulic oil pressure can be secured when other factories are set to neutral. Since the breaker power is mainly used as the PTO actuator, the breaker is almost stopped and used, so almost all the hydraulic oil discharged from both hydraulic pumps P1 and P2 is used for the breaker work. Hydraulic oil supplied to the PTO directional control valve 56 without the aid of a throttle restricts loss and enables efficient work.
- the blade directional switching valve 53 does not supply hydraulic oil for the blade cylinder 14 to the hydraulic oil suction port from the first center bypass oil passage 32, and throttles only from the joint oil passage 33c. Hydraulic oil for blade cylinders 14 is supplied via 2.
- the hydraulic oil supply oil passage via the throttle 72 is substantially the same as the joint oil passage 33 c between the check valves 40 and 41, counting from each check valve 40 and 41.
- the third branch from the check valve 40, the fourth check valve 41, and the fourth branch) in other words, in the bypass oil passage 33, the directional control valve 50 for both traveling motors 50 It branches off from approximately the middle point between the hydraulic oil supply passages to L ⁇ 50 R.
- a lead circuit is formed on the turning direction switching valve 54 on the upper side of the arm direction switching valve 55, and the turning direction switching is performed.
- the valve 54 is in the operating position, the valve is closed with respect to the bleed circuit. .
- the turning direction switching valve 54 is an eight-port three-position switching control valve, in which a bleed passage that opens when the neutral position is established and closes when the operating position is formed is formed.
- the bleed oil passage 35 through the throttle 75 is connected to the primary side of the bleed passage of the turning direction switching valve 54, and the force and the secondary side of the bleed passage of the turning direction switching valve 54 are connected.
- the second center bypass oil passage 32 between the arm directional switching valve 55 and the PTO directional switching valve 56 ie, the lower side of the arm directional switching valve 55
- the first sensor bypass oil The junction with road 31.
- a lead oil passage 35 branching from the first center bypass oil passage 31 leading to the arm direction switching valve 55 (neutral connection portion 59) is passed through the turning direction switching valve 54, It can be opened and closed in conjunction with the turning direction switching valve 54.
- the bleed oil passage 35 is shut off by the swing direction switching valve 54 that is in the operating position.
- the second center bypass oil passage 32 is shut off from the arm direction switching valve 55. Therefore, the hydraulic oil from the second center bypass oil passage 32 is sucked into the hydraulic oil suction port of the turning direction switching valve 54 via the check valve 44 (further, the combined oil passage 3 3 c The hydraulic oil is also sucked through the throttle 75 and the check valve 49.)
- the hydraulic oil suction port of the arm directional switching valve 55 is connected to the first center bypass oil passage 31.
- the turning direction switching valve 54 becomes the neutral position, and the bleed circuit is opened. Therefore, the oil in the first center bypass oil passage 31 flows through the check valve 68 to the neutral connection portion 59, and passes through the turning direction switching valve 54. And is supplied to the hydraulic oil suction port of the arm directional switching valve 55, and at the upstream side of the neutral connection portion 59, a pre-formed oil passage 35 having a throttle 75 is provided. The bleed oil passes through the turning direction switching valve 54 and flows out to the second center bypass oil passage 32 on the lower side of the arm direction switching valve 55.
- a spool is generally used in the turning direction switching valve 54 to constitute a bleed circuit.
- the throttle circuit 75 incorporated in the bleed oil passage 35 on the primary side of the turning direction switching valve 54 in the hydraulic circuit 100a of FIG.
- a throttle 75 is incorporated in a spool in the turning direction switching valve 54.
- each unit in the present embodiment has the same configuration and function as those shown in FIGS. 4 to 7 in the hydraulic circuit 100.
- the first center bypass oil passage 31 is provided with a swing directional switching valve 58, a boom directional switching valve 51, a bucket directional switching valve 52, and one of the left and right traveling motors from the upstream side.
- Directional switching valve 50 R blade directional switching valve 53 3 tandem (serial) connected to the second center bypass oil passage 32 is a direction switching valve 57 for option, a direction switching valve 54 for turning, and a left and right traveling motor for the traveling motor (in this embodiment, for the left traveling motor 15 L) direction switching valve 50 from the upstream side
- the L, arm directional switching valve 55 and the PTO directional switching valve 56 are connected in tandem.
- the most downstream end of the first center bypass oil passage 31 is a neutral connection of the second center bypass oil passage 32 between the left traveling direction switching valve 50 L and the arm direction switching valve 55. It joins the connecting portion 59 and the combined oil of the two center bypass oil passages 31 and 32 can be supplied to the arm directional switching valve 55 as the hydraulic oil of the arm cylinder 29.
- the second center bypass oil passage 32 which has joined the first center bypass oil passage 31 in this way, communicates with the tank oil passage 34 after passing through the PTO directional switching valve 56. .
- the swing direction switching valve 58 is provided at a branch point between the first center bypass oil passage 31 from the discharge oil passage of the first hydraulic pump P1 and the branch oil passage 33a, and a boom direction switching valve. Hydraulic oil for swing cylinder 17, bucket cylinder 23, and bucket cylinder 24 can be supplied to 51 and bucket directional control valve 52 from first center bypass oil passage 31, respectively. .
- the optional directional control valve 57 is connected to the branch point between the second center bypass oil passage 32 and the branch oil passage 33b from the discharge oil passage of the second hydraulic pump P2, and to the arm
- the directional control valve 55 and the PTO directional control valve 56 are connected to the first center bypass oil passage 31 and the second center bypass oil passage 32 after merging with the optional center and arm cylinders, respectively. 29. Hydraulic oil for PTO-equipped factory can be supplied.
- a parallel oil passage 33 is provided for supplying the hydraulic fluid for actuation to the directional control valve to each of the directional control valves, but the upstream of the check valve 40 is provided.
- the hydraulic oil supply oil passages to the boom directional switching valve 51, the bucket directional switching valve 52, and the right traveling directional switching valve 50R are branched from the side branch oil passage 33a.
- Check valve 4 1 From the upstream branch oil passage 3 3 b, the hydraulic oil supply oil passage to the turning direction switching valve 54 is branched, and the combined oil passage 33 c force, etc. Hydraulic oil supply oil passages to the directional switching valve 50 L and the directional switching valve 53 for blades are branched.
- the hydraulic circuit 101 is provided with hydraulic fluid supply positions for the boom cylinder 23, the bucket cylinder 24, and the swing motor 13 for the left and right traveling motors 15L and 15R, respectively. Hydraulic oil is supplied from the downstream side, so that the driving of work implement 2 has priority over traveling.
- left-right traveling direction switching valve 50 L ⁇ 5 0 R is located upstream of the boom directional control valve 51, the bucket directional control valve 52, the turning directional control valve 54, etc. to receive hydraulic oil, thereby improving the straight running performance during work. It is also conceivable to secure them.
- a preed oil passage 35 is connected to one of the bleed switching valves 85.
- a throttle may be provided at an arbitrary opening degree. An embodiment in this regard will be described later with reference to FIGS. 26 and 27.
- the bridge switching valve 85 is a three-port three-position type, of which two ports are a P port and a T port for the second center bypass oil passage 32, and both ports are always in communication. ing.
- the other is a pre-pipe oil suction port, which is connected to the pre-pipe oil passage 35.
- the bleed oil passage 35 communicates with the second center bypass oil passage 32 within the bleed switching valve 85 to reach the neutral junction portion 59. Short-circuit the pressure oil in the first center bypass oil passage 31 to the PTO directional switching valve 56.
- the bleed switching valve 85 is set to one of the two positions other than the neutral position, the preed oil suction port is shut off from the second center bypass oil passage 32 in the preed switching valve 85. .
- the bleed switching valve 85 is linked to an operation lever 87 for switching the turning direction switching valve 54, that is, in conjunction with switching of the turning direction switching valve 54 between the three positions. It can be switched. Therefore, when the turning direction switching valve 54 is set to the neutral position, the bridge switching valve 85 is set to the neutral position, and the bridge oil passage 31 is communicated with the second center bypass oil passage 32 to turn. When the directional control valve 54 is in the operating position, the bleed oil passage 31 is shut off from the second center bypass oil passage 32.
- the neutral connection portion 59 connects to the bleed oil passage 35.
- a check valve 68 for preventing the flow of air is provided. That is, the oil from the second center bypass oil passage 32, which flows into the first center bypass oil passage 31 from the neutral connection portion 59, is prevented from flowing into the bridge oil passage 35.
- the omnidirectional switching valve and the bleed switching valve 85 of the hydraulic circuit 101 are used in this embodiment. Is a manual type, and is operated by various levers, pedals, etc. provided on the revolving unit 8 (however, the bleed switching valve 85 is a revolving lever for switching the reversing direction switching valve 54). Any of these forces may be replaced with, for example, a hydraulic pilot type ⁇ electromagnetic solenoid type. An embodiment in which the hydraulic pilot type is replaced will be described later with reference to FIGS. 29 and 30.
- the hydraulic circuit 101 is controlled by the first hydraulic pump P while adjusting the amount by a bridge circuit including a bleed switching valve 45 and a check valve 46.
- the discharge oil from one force is also supplied as hydraulic oil for the arm cylinder 29. That is, when the damper cylinder 29 is driven independently, in addition to the hydraulic oil from the second hydraulic pump P2, the hydraulic oil from the first hydraulic pump P1 adjusted by the bleed circuit is also supplied as hydraulic oil. Do it.
- FIG. 10 shows a state in which the directional switching valve and the bleed switching valve 85 for all factories are neutral, and accordingly, the first center bypass oil passage 3 1 and the second center bypass oil passage 3 2 Is open to all lines, and the pressure oil discharged from both pumps P 1 and P 2 passes through both center bypass oil passages 31 and 32 and the tank oil passage 34 shown in bold in FIG. 10. Is discharged to the oil tank.
- FIG. 11 shows a case where only the arm 5 is driven.
- the arm switching valve 55 is switched to the operating position, and the pressure oil in the second center bypass oil passage 32 is supplied to the arm cylinder 29 via the arm direction switching valve 55. Is done.
- the bleed switching valve 85 is in the neutral position, and opens to the bleed oil passage 31a to supply the arm switching valve 55 as the operating oil for the arm cylinder 29.
- the supplied oil from the first center bypass oil passage 31 is short-circuited to the second center bypass oil passage 32 on the upstream side of the PTO directional control valve 56 before reaching the neutral connection portion 59. Oil from the first hydraulic pump P1 is not supplied to the arm switching valve 55 as hydraulic oil. Accordingly, since only the hydraulic oil from the second hydraulic pump P2 is supplied to the arm cylinder 29, the arm 5 is driven only by the second hydraulic pump P2.
- the reversing direction switching valve 54 is switched to the operating position, and the hydraulic pressure from the two pumps P 1 and P 2 flows along the path shown in FIG. 12. It is discharged after passing.
- the position of the bleed switching valve 85 is also switched due to the interlocking configuration of the bleed switching valve 85 and the turning direction switching valve 54, and the bleed oil passage 31a is closed.
- the pressure oil from the first hydraulic pump P1 does not fall out of the bleed oil passage 31a but joins the second connection bypass oil passage 32 from the neutral connection portion 59 via the check valve 68 through the check valve 68.
- the second center bypass oil passage 32 passes through the arm direction switching valve 55 at the neutral position, and is discharged to the oil tank. Then, only the pressure oil from the second hydraulic pump P 2 (pressure oil from the branch oil passage 33 b) is supplied to the swing motor 13 through the swing direction switching valve 54, and the swing body 8 force It is driven only by the second hydraulic pump P2.
- the arm direction switching valve 55 and the turning direction switching valve 54 are in the operating position, and the bleed switching valve 85 is a bleed oil passage.
- the valve is closed with respect to 31a, and the hydraulic oil from both pumps P1 and P2 is discharged through a path as shown in FIG.
- the hydraulic oil from the second hydraulic pump P 2 is supplied from the branch oil passage 3 3 b to the swing motor 13 via the swing direction switching valve 54, and the swing body 8 is driven only by the second hydraulic pump P 2 Is done.
- the pressure oil from the first hydraulic pump P 1 is blocked from flowing into the bleed switching valve 85, is supplied to the arm cylinder 29 via the arm directional switching valve 55, and the arm 5 is It is driven only by the hydraulic pump P1. That is, in the hydraulic circuit 101, the swing motor 13 and the arm cylinder 29 are driven by different pumps.
- the boom directional control valve 51 is connected to the branch oil passage 33 a through which only the discharge oil from the first hydraulic pump P 1 is supplied. 3 is supplied with hydraulic oil for the bucket, and the directional valve 52 for the bucket is Hydraulic oil for the bucket cylinder 24 is supplied from 33 a and the first center bypass oil passage 31. Then, the turning direction switching valve 54 is supplied with hydraulic oil for the turning motor 13 from a branch oil passage 33 b to which only the discharge oil from the second hydraulic pump P 2 is supplied.
- the second pump P 2 (Slightly includes the hydraulic oil from the bleed first hydraulic pump P1.)
- the first hydraulic pump P Hydraulic oil is supplied from 1.
- the arm cylinder 29 and the swing motor 13 are both included in the independent circuit on the second hydraulic pump P2 side as shown in FIG. 3 (a).
- the first hydraulic pump P 1 when closing the bleed oil passage 35 of the bleed switching valve 85, the first hydraulic pump P 1 is sent to the arm cylinder 29 via the check valve 68. Pressure oil can be supplied.
- pumps having different independent circuits can be used as shown in FIG. 3 (b). For this reason, the arm cylinder 29 and the swing motor 13 are driven by different pumps, and in this case also, simultaneous operation is exhibited.
- the respective actuators are driven by respective independent circuits. That is, since one actuator is driven by one pump each time, simultaneous operability is favorably exhibited.
- FIG. 16 is a list showing the suitability of simultaneous operability in driving the arm 5, the bucket 4, and the boom 6 by the hydraulic circuit 101 and in turning the revolving unit 8.
- the simultaneous operability of the arm 5 and the turning is improved by the opening and closing effect of the bleed switching valve 85 as compared with the conventional two-pump hydraulic circuit for the excavation turning work vehicle.
- the hydraulic circuit 101 is a two-pump system, but at low cost by adding a few parts such as a check valve 68 and a bleed switching valve 85. To obtain simultaneous operation equal to three pump system Can be.
- the arm cylinder 29 is the first center bypass oil passage.
- FIG. 15 shows the hydraulic circuit 101 when the PTO is driven independently.
- the PTO directional control valve 56 has an oil passage 966a, 96 that is to be connected to the port of the PT0 actuator (normally a breaker). b is connected, and is provided downstream of the bleed switching valve 85 in the combined flow path of the two center bypass oil passages 31 and 32.
- the PTO directional control valve 56 receives the discharge oil from both hydraulic pumps P 1 and P 2 as hydraulic oil for the PTO actuator, and drives the PTO.
- sufficient working oil can be supplied to the working machine, and the operability of the working machine can be improved.
- the hydraulic oil from the second hydraulic pump P 2 is supplied, and the hydraulic oil in the independent circuit of the second hydraulic pump P 2 is supplied.
- any of the other directional control valves is in the operating position, hydraulic oil is supplied from the first hydraulic pump P1.
- FIGS. 17 and 18 The hydraulic circuit 101a shown in FIGS. 17 and 18 described below enables the boom 6, the arm 5, and the swing body 8 to be driven simultaneously.
- Fig. 17 shows the omnidirectional switching valve in the neutral position
- Fig. 18 shows the boom directional switching valve 51, the arm directional switching valve 55, and the turning directional switching valve 54.
- FIG. 19 is a list showing the suitability of the simultaneous operability in the driving of the arm 5, the bucket 4, and the boom 6 by the hydraulic circuit 101a, and the swing of the swing body 8.
- the hydraulic oil discharged from the second hydraulic pump P2 is supplied to the turning motor 13 and A part of the pressure oil is also supplied to the arm cylinder 29.
- Other configurations are the same as those of the hydraulic circuit 101.
- the turning switching valve 54 provided in the hydraulic circuit 101 connects the P port (upper side of the second sender bypass oil passage 32) and the T port (lower side of the second center bypass oil passage 32).
- the connecting oil passage is shut off so that the hydraulic oil discharged from the second hydraulic pump P2 does not flow into the oil tank when the turning motor 13 is driven.
- the turning switching valve 54 provided in the hydraulic circuit 101a connects the oil passage connecting the P port and the T port at each operating position, as shown in Figs.
- a bleed restrictor 54a is provided in the connection oil passage.
- both the driving of the arm 5 and the boom 6 and the turning of the revolving unit 8 can be performed at the same time as in the three-pump system, even though the two-pump system is used. ing.
- Hydraulic circuit 101b which is another embodiment capable of simultaneously driving both the boom 6 and the arm 5 and turning the revolving unit 8, will be described with reference to FIGS. 20 to 22.
- Fig. 20 shows the omnidirectional switching valve in the neutral position
- Fig. 21 shows the boom directional switching valve 51, the arm directional switching valve 55, and the turning directional control valve 54.
- FIG. 22 is a list showing the suitability of simultaneous operability in driving the arm 5, the baguette 4, the boom 6 by the hydraulic circuit 10 lb, and the turning of the revolving unit 8 in the operating position. .
- the boom directional switching valve 51 in the hydraulic circuit 101 is improved so that the hydraulic oil discharged from the first hydraulic pump P 1 is supplied to the boom cylinder 23 and A part of the pressurized oil is also supplied to the arm cylinder 29.
- Other configurations are the same as those of the hydraulic circuit 101.
- the boom directional control valve 51 provided in the hydraulic circuit 101 has the P port (upper side of the first center bypass oil passage 31) and the T port (lower side of the first center bypass oil passage 31) in the operating position.
- the hydraulic oil discharged from the first hydraulic pump P1 is prevented from flowing into the oil tank.
- the boom directional control valve 51 provided in the hydraulic circuit 101b connects the P port and the T port at each operating position as shown in FIGS. 20 and 21.
- the oil passage is connected, and a bleed throttle 51a is provided in the connection oil passage.
- the hydraulic oil from the first hydraulic pump P1 is supplied to the boom cylinder 23, and a part of the hydraulic oil is excessively driven by the boom cylinder 23. It is also supplied to the arm cylinder 29 as a stream.
- FIGS. 23 to 25 show the omnidirectional valve in the neutral position.
- the directional control valve 51 for the arm, the directional control valve for the arm 55, and the directional control valve for turning 54 are in the operating position.
- Fig. 25 shows the arm 5 with the hydraulic circuit 101c.
- FIG. 9 is a list showing the suitability of simultaneous operability in driving the bucket 4, the boom 6, and turning the revolving unit 8.
- the hydraulic circuit 101c is configured to take advantage of both features of the hydraulic circuit 101a and the hydraulic circuit 101b.
- the boom directional control valve 51 communicates the P port and the T port to the first center bypass oil passage 31 via the preed throttle 51 a when in the operating position.
- the directional control valve 54 also communicates the P port and the T port to the second center bypass oil passage 32 via the lead restrictor 54a when in the operating position. Otherwise, the same configuration as the hydraulic circuit 101 can be used.
- the surplus flow of the pressure oil supplied from the first hydraulic pump P1 to the boom cylinder 23 and the surplus flow of the hydraulic oil from the second hydraulic pump P2 are supplied to the rotating motor 13
- the surplus flow of the pressurized oil is supplied to the arm cylinder 29 so that the arm 5 can be driven.
- the hydraulic circuit 101c has a three-pump system, which is a two-pump system, while simultaneously performing both the drive of the arm 5 and the boom 6 and the turning of the revolving unit 8. Operability comparable to the above.
- the hydraulic circuit 101 d shown in FIGS. 26 and 27 is provided with the hydraulic circuit 101 in the hydraulic circuit 101 in order to improve the operability of the arm 5.
- Fig. 26 shows a state in which the omnidirectional switching valve is in the neutral position
- Fig. 27 shows a state in which the arm directional switching valve 55 is in the operating position. Show ing.
- a throttle ⁇ 5 is provided in the bleed switching valve 85 in the hydraulic circuit 101, and one of the bleeds is branched from the first center bypass oil passage 31.
- the other end is connected to an oil passage 35, and the other end is connected to a second center bypass oil passage 32 (a joint flow passage with the first center bypass oil passage 31) passing through the bridge switching valve 85.
- a throttle can be formed in the spool extending between the ports, and various openings can be made simply by replacing the spool. It can be adjusted at any time. The same can be said of the boom directional switching valve 15 1 and the turning directional switching valve 15 4 in the hydraulic circuits 101 a ⁇ 101 b ⁇ 101 c.
- a preed switching valve 85 having a throttle 75 is provided.
- the provision is also applicable to the above-described hydraulic circuit 101a ⁇ 101b ⁇ 101c. The same effect is exerted by these hydraulic circuits with respect to the improvement of the operability of the arm 5 by the throttle 75.
- the positions of the turning direction switching valve 54 and the arm direction switching valve 55 may be interchanged as in a hydraulic circuit 101 e shown in FIG.
- a hydraulic circuit 10 having a configuration in which a throttle 75 is provided on a bleed switching valve 85 is provided. If the positions of the directional control valve 5 and the directional control valve 5 5 for the arm are interchanged in this way at 1 d, the turning motor 13 will receive the hydraulic oil from the second hydraulic pump P 2, A considerable amount of pressurized oil flows in from one hydraulic pump P1, and a large driving force can be obtained.
- the hydraulic circuit 101 e is connected to the second center bypass oil passage 32 by the arm directional switching valve 55, the left traveling directional switching valve 50 L, and the turning directional switching valve 54.
- the neutral connection part 59 which is the junction of the second center bypass oil passage 32 and the first center bypass oil passage 31, is connected to the turning direction switching valve 54 and its one upstream side. Is provided between the left direction switching valve 50 L and the left direction switching valve 50 L.
- the switching of the hydraulic oil supply position to the swing motor 13 and the arm cylinder 29 can be applied to the hydraulic circuits 101 a to 101 d.
- the hydraulic circuit 101c is configured to obtain the same simultaneous operability of three factories.
- the three factories are the arm cylinder 29 of the arm 5, the baguette cylinder 24 of the baguette 4, and the rotating motor 13 of the revolving unit 8. Therefore, even if the hydraulic oil supply position is changed in these factories, even if the three factors are operated simultaneously, the same operability can be obtained.
- FIGS. 29 and 30 showing an embodiment in which a port-type directional switching valve is used.
- the hydraulic circuit 101f ⁇ 101g of the present invention will be described.
- the re-use directional control valve 154 is a directional control valve whose operating method is a hydraulic pilot type.
- the pilot operated valves for operating the directional control valves are: boom pilot operated valve 1 1 1, bucket pilot operated valve 1 1 2, arm pilot operated valve 1 1 3, swivel pilot operated valve 1 1 4, etc. And a pilot pump P3 for operating each of the operation valves.
- the switching valve of the factory is switched by a corresponding pilot operated valve.
- the hydraulic pump P 3 has only a pilot pump function. It is not a three-pump hydraulic circuit for turning vehicles.
- a branch is provided in each of the pilot oil passages on the outward and return routes.
- One of the branched pipe oil passages is connected to the pilot operating section of the turning direction switching valve 154, and the other is connected to the pilot operating section of the bleed switching valve 185.
- the pilot hydraulic pressure is supplied to the operating parts of the directional switching valve 15 4 and the bleed switching valve 18 5 by the operation of the pilot control valve 1 14 It can be switched. Further, since the bidirectional switching valve is interlocked by operating the turning pilot operation valve 114, reliable operation of both switching valves can be realized.
- a bleed switching valve 185 for three-port three-position switching is replaced by a hydraulic pilot-type pre-switching valve 285 for three-port two-position switching.
- a high pressure selection valve is installed in the pilot oil passage
- the high-pressure selection valve 1 15 is a pipe connected to the secondary side of the swivel pilot operated valve 1 14 It is arranged so as to straddle the outbound route and the return route of the lot oilway. If one of the pilot oil pressures flowing in the forward and return paths is higher, the pilot oil pressure is higher than that of the high pressure selector valve 115, and the pilot port operating section of the bridge switching valve 285 is operated. In addition, the bleed switching valve 285 is switched to the operating position. When the hydraulic pressure flowing in the forward path and the hydraulic pressure flowing in the return path are equal, the bleed switching valve 285 returns to the neutral position by the pressure of the spring provided inside.
- the operation of the turning pilot operation valve 114 allows the turning direction switching valve 154 and the bleed switching valve 285 to be switched in conjunction with each other. Since the two switching valves are interlocked by operating the turning pilot operation valve 114, reliable operation of the two-way switching valve can be realized. In addition, the operation balance can be favorably maintained when any one of the boom 6, the arm 5, the baguette 4, and the revolving unit 8 is simultaneously operated.
- any of the hydraulic circuits 101 a to 101 e described above. can also be applied.
- the hydraulic circuit 101 is provided with the bleed switching valve 85 so as to open and close the bridge oil passage 35 to secure a large operating force when the arm 5 is alone. And the revolving unit 8 can be operated at the same time. Force The effect is as shown in the hydraulic circuit 100a and 100b described above. This is the same as that by the switching valve 54. That is, in the embodiment of the hydraulic circuit 101 and the like (particularly, the hydraulic circuit 101 d), instead of the bleed switching valve 85, the turning direction switching valve 54 is improved and the arm operation A bleed circuit may be incorporated.
- the bleed restrictor 51 in the boom directional control valve 51 and the bleed restrictor 54 in the turning directional control valve 54 are provided.
- the present invention provides a two-pump hydraulic circuit for an excavation and turning work vehicle that has good traveling performance during work and good operability during two or more operations. It can contribute to the manufacture of excavation and turning work vehicles.
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- General Engineering & Computer Science (AREA)
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- Civil Engineering (AREA)
- Structural Engineering (AREA)
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Description
Claims
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR1020037003530A KR100804665B1 (ko) | 2000-09-12 | 2001-09-10 | 굴착선회 작업차의 유압회로 |
US10/380,146 US6915600B2 (en) | 2000-09-12 | 2001-09-10 | Hydraulic circuit of excavating and slewing working vehicle |
EP01965568A EP1384827A4 (en) | 2000-09-12 | 2001-09-10 | HYDRAULIC VEHICLE CIRCUIT FOR CARRYING OUT EXCAVATION AND PIVOTING OPERATIONS |
US11/044,439 US6971195B2 (en) | 2000-09-12 | 2005-01-27 | Hydraulic circuit of excavating and slewing working vehicle |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2000-276201 | 2000-09-12 | ||
JP2000276201A JP2002088823A (ja) | 2000-09-12 | 2000-09-12 | 掘削旋回作業車の油圧回路 |
JP2001187090A JP4569940B2 (ja) | 2001-06-20 | 2001-06-20 | バックホーの油圧回路 |
JP2001-187090 | 2001-06-20 |
Related Child Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10380146 A-371-Of-International | 2001-09-10 | ||
US11/044,439 Division US6971195B2 (en) | 2000-09-12 | 2005-01-27 | Hydraulic circuit of excavating and slewing working vehicle |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2002022969A1 true WO2002022969A1 (fr) | 2002-03-21 |
Family
ID=26599733
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2001/007856 WO2002022969A1 (fr) | 2000-09-12 | 2001-09-10 | Circuit hydraulique de vehicule servant a realiser des operations d'excavation et de pivotement |
Country Status (4)
Country | Link |
---|---|
US (2) | US6915600B2 (ja) |
EP (1) | EP1384827A4 (ja) |
KR (1) | KR100804665B1 (ja) |
WO (1) | WO2002022969A1 (ja) |
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DE102004031056B4 (de) * | 2003-06-25 | 2006-02-09 | Volvo Construction Equipment Holding Sweden Ab | Hydraulischer Kreislauf für eine optionale Vorrichtung einer schweren Baumaschine, welcher einen Zusammenfluss-Kolben für den Ausleger verwendet |
DE10329929B4 (de) * | 2003-02-12 | 2010-11-18 | Volvo Construction Equipment Holding Sweden Ab | Hydrauliksystem für eine Baugerät mit einer optionalen Vorrichtung |
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US9702424B2 (en) | 2014-10-06 | 2017-07-11 | ClearMotion, Inc. | Hydraulic damper, hydraulic bump-stop and diverter valve |
US9611619B1 (en) | 2015-10-22 | 2017-04-04 | Cnh Industrial America Llc | Hydraulic hybrid circuit with energy storage for excavators or other heavy equipment |
US10119556B2 (en) * | 2015-12-07 | 2018-11-06 | Caterpillar Inc. | System having combinable transmission and implement circuits |
EP3434910B1 (en) * | 2016-03-22 | 2024-02-28 | Sumitomo (S.H.I.) Construction Machinery Co., Ltd. | Shovel and control valve for shovel |
KR102080086B1 (ko) * | 2019-12-31 | 2020-02-24 | 대호 (주) | 동시 작동이 가능한 트랙터 유압장치 |
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JP2767482B2 (ja) | 1990-05-18 | 1998-06-18 | 株式会社ゼクセル | スタック型油圧制御弁装置 |
JP2760702B2 (ja) | 1992-06-19 | 1998-06-04 | 株式会社クボタ | 作業車の油圧回路構造 |
JPH062352A (ja) | 1992-06-19 | 1994-01-11 | Matsushita Refrig Co Ltd | 脱臭装置付便器 |
JPH078601U (ja) | 1993-06-30 | 1995-02-07 | 豊興工業株式会社 | 油圧装置 |
JPH10195933A (ja) | 1997-01-16 | 1998-07-28 | Hitachi Constr Mach Co Ltd | 建設機械の油圧駆動装置 |
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2001
- 2001-09-10 WO PCT/JP2001/007856 patent/WO2002022969A1/ja active Application Filing
- 2001-09-10 KR KR1020037003530A patent/KR100804665B1/ko not_active IP Right Cessation
- 2001-09-10 US US10/380,146 patent/US6915600B2/en not_active Expired - Fee Related
- 2001-09-10 EP EP01965568A patent/EP1384827A4/en not_active Withdrawn
-
2005
- 2005-01-27 US US11/044,439 patent/US6971195B2/en not_active Expired - Fee Related
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JPH078601Y2 (ja) * | 1987-11-10 | 1995-03-01 | 株式会社クボタ | バックホウの油圧回路 |
JPH0344204U (ja) * | 1989-09-11 | 1991-04-24 | ||
EP0439166A1 (en) * | 1990-01-26 | 1991-07-31 | Zexel Corporation | Stacked type hydraulic control valve system |
JP2000154805A (ja) * | 1998-11-19 | 2000-06-06 | Seirei Ind Co Ltd | 掘削作業機の制御弁ユニット |
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE10329929B4 (de) * | 2003-02-12 | 2010-11-18 | Volvo Construction Equipment Holding Sweden Ab | Hydrauliksystem für eine Baugerät mit einer optionalen Vorrichtung |
DE102004031056B4 (de) * | 2003-06-25 | 2006-02-09 | Volvo Construction Equipment Holding Sweden Ab | Hydraulischer Kreislauf für eine optionale Vorrichtung einer schweren Baumaschine, welcher einen Zusammenfluss-Kolben für den Ausleger verwendet |
Also Published As
Publication number | Publication date |
---|---|
US6971195B2 (en) | 2005-12-06 |
US6915600B2 (en) | 2005-07-12 |
US20040083629A1 (en) | 2004-05-06 |
EP1384827A4 (en) | 2009-04-01 |
KR20030036775A (ko) | 2003-05-09 |
EP1384827A1 (en) | 2004-01-28 |
US20050144941A1 (en) | 2005-07-07 |
KR100804665B1 (ko) | 2008-02-20 |
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