CN113323070B - Excavator movable arm hydraulic system and control method thereof - Google Patents
Excavator movable arm hydraulic system and control method thereof Download PDFInfo
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- CN113323070B CN113323070B CN202110720914.5A CN202110720914A CN113323070B CN 113323070 B CN113323070 B CN 113323070B CN 202110720914 A CN202110720914 A CN 202110720914A CN 113323070 B CN113323070 B CN 113323070B
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- 238000000034 method Methods 0.000 title claims abstract description 27
- 239000003921 oil Substances 0.000 claims abstract description 414
- 239000010720 hydraulic oil Substances 0.000 claims abstract description 8
- 238000004891 communication Methods 0.000 claims description 5
- 239000007788 liquid Substances 0.000 claims description 5
- 230000002159 abnormal effect Effects 0.000 abstract description 10
- 238000007789 sealing Methods 0.000 abstract description 9
- 239000012530 fluid Substances 0.000 abstract 1
- 238000012423 maintenance Methods 0.000 description 15
- 238000000926 separation method Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 4
- 238000012986 modification Methods 0.000 description 2
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- 238000006467 substitution reaction Methods 0.000 description 2
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- 230000009286 beneficial effect Effects 0.000 description 1
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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
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- Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- Civil Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Structural Engineering (AREA)
- Operation Control Of Excavators (AREA)
- Fluid-Pressure Circuits (AREA)
Abstract
The invention discloses a movable arm hydraulic system of an excavator, which comprises a hydraulic oil tank, a main pump, a movable arm oil cylinder and a main valve, wherein an oil inlet of the first main valve can be communicated with a working oil port of the second main valve; the first main valve oil return port is communicated with the first main valve working oil port; the first main valve working oil port is communicated with a small cavity oil inlet of the movable arm oil cylinder, the second main valve working oil port is communicated with a large cavity oil inlet of the movable arm oil cylinder, a reversing valve is connected between the small cavity oil inlet and the large cavity oil inlet, and the reversing valve can be closed or communicated with the large cavity and the small cavity. A control method of the excavator boom hydraulic system comprises the following steps: s21, the controller starts the main pump to make the first main valve oil inlet connect with the second main valve working oil port, the first main valve oil return port connect with the first main valve working oil port, S22, the controller starts the change valve. Avoid air to separate out from the fluid and cause sealing member burn, abnormal sound, components and parts cavitation, reduce later stage cost.
Description
Technical Field
The invention relates to a movable arm hydraulic system of an excavator and a control method thereof.
Background
In the prior art, a movable arm of an excavator is controlled to lift by a hydraulic system, when the movable arm is required to lift, oil is fed into a small cavity of a movable arm oil cylinder, and oil is discharged from a large cavity of the movable arm oil cylinder, so that the movable arm can lift; when the movable arm is required to descend, the small cavity of the movable arm oil cylinder discharges oil, and the large cavity of the movable arm oil cylinder feeds oil, so that the movable arm descends.
The above technical solution has the following disadvantages: the large cavity of the movable arm oil cylinder cannot obtain compensation oil in time when the movable arm rapidly descends due to the fact that large pressure loss is generated when oil flows caused by the existence of the small-drift-diameter hose, so that the large cavity of the movable arm oil cylinder is in a negative pressure state, air is separated out of the oil to cause burning of sealing elements, abnormal sound and cavitation of components, and later-period operation and maintenance cost is increased.
Disclosure of Invention
The invention aims to provide a movable arm hydraulic system of an excavator and a control method thereof, aiming at solving the problems, and avoiding burning, abnormal sound and cavitation of components of a sealing element caused by separation of air from oil.
In order to achieve the above object, the present invention discloses an excavator boom hydraulic system, which includes a hydraulic oil tank, a main pump, a boom cylinder, and a main valve, wherein the main valve includes a first main valve oil inlet P11, a first main valve oil return port T11, a first main valve working oil port a1, and a second main valve working oil port B1, and the first main valve oil inlet P11 can be closed or communicated with one of the first main valve working oil port a1 and the second main valve working oil port B1; the first main valve oil return port T11 can be closed or communicated with one of the second main valve working oil port B1 and the first main valve working oil port a 1; the first main valve working oil port A1 is communicated with a small cavity oil inlet P31 of the movable arm oil cylinder, the second main valve working oil port B1 is communicated with a large cavity oil inlet P32 of the movable arm oil cylinder, a reversing valve is connected between the small cavity oil inlet P31 and the large cavity oil inlet P32, and the reversing valve can close or communicate the large cavity and the small cavity. In an initial state, all oil ports of the main valve are in closed positions, and the movable arm oil cylinder is in any stop position.
When the boom is required to ascend, a valve core of the main valve moves, the first main valve oil inlet P11 is communicated with the first main valve working oil port A1, and the first main valve oil return port T11 is communicated with the second main valve working oil port B1. At the moment, the small cavity of the boom cylinder is filled with oil, the large cavity of the boom cylinder is filled with oil, and the boom is lifted.
When the boom is required to descend, the valve core of the main valve moves, the first main valve oil inlet P11 is communicated with the second main valve working oil port B1, and the first main valve oil return port T11 is communicated with the first main valve working oil port A1. At the moment, the large cavity of the movable arm oil cylinder takes oil in, and the small cavity of the movable arm oil cylinder takes oil out, so that the movable arm descends; meanwhile, the reversing valve is started, so that oil in the small cavity of the movable arm oil cylinder enters the large cavity of the movable arm oil cylinder, the oil pressure in the large cavity of the movable arm oil cylinder is improved, air is prevented from being separated out from oil liquid to cause burning of sealing elements, abnormal sound and cavitation of components, and the later-period operation and maintenance cost is reduced.
Preferably, the main valve further includes a boom-up pilot oil port a1 and a boom-down pilot oil port B1, and when the boom-up pilot oil port a1 obtains pilot oil, the first main valve oil inlet P11 communicates with the first main valve working oil port a1, and the first main valve oil return port T11 communicates with the second main valve working oil port B1; when the movable arm descends to the pilot oil port B1 to obtain pilot oil, the first main valve oil inlet P11 is communicated with the second main valve working oil port B1; the first main valve return port T11 communicates with the first main valve working port a 1. When the valve is used, the valve core of the main valve is driven by pilot oil, the structure is compact, the service life is long, and the later-period operation and maintenance cost is reduced.
Preferably, the reversing valve comprises a reversing valve oil inlet P2 and a reversing valve working oil port A2, and the reversing valve oil inlet P2 can be closed or communicated with the reversing valve working oil port A2. When the reversing valve is used, the reversing valve adopts a two-position two-way valve, the structure is compact, the service life is long, and the later-period operation and maintenance cost is reduced.
Preferably, the boom-up pilot oil port a1 is communicated with a first pilot oil interface, the boom-down pilot oil port b1 is communicated with a second pilot oil interface, and the reversing valve further comprises a reversing pilot oil port a2, and the reversing pilot oil port a2 is communicated with the second pilot oil interface. When the reversing valve is used, the valve core of the reversing valve is driven by pilot oil, the structure is compact, the service life is long, and the later-period operation and maintenance cost is reduced; meanwhile, when the second pilot oil port supplies oil to the boom-down pilot oil port b1, oil is simultaneously supplied to the reversing pilot oil port a1, boom-down and the reversing valve opening are simultaneously performed, so that oil in the boom cylinder small cavity enters the boom cylinder large cavity.
Preferably, the reversing valve comprises an electromagnetic ball valve. When in use, the flow of the reversing valve is convenient to adjust.
Preferably, a small cavity hydraulic sensor is installed in the small cavity of the boom cylinder, and a large cavity hydraulic sensor is installed in the large cavity of the boom cylinder. When the movable arm oil cylinder hydraulic pressure measuring device is used, the small cavity hydraulic pressure sensor and the large cavity hydraulic pressure sensor are used for measuring hydraulic values of the small cavity and the large cavity of the movable arm oil cylinder, and reference is provided for subsequent decision making.
A control method of a boom hydraulic system of an excavator as described above, the control method comprising a boom-down flow including the steps of:
s21, the controller starts the main pump and controls the valve core of the main valve to move, so that the first main valve oil inlet P11 is communicated with the second main valve working oil port B1, the first main valve oil return port T11 is communicated with the first main valve working oil port A1, when the movable arm needs to descend, the valve core of the main valve moves, the first main valve oil inlet P11 is communicated with the second main valve working oil port B1, and the first main valve oil return port T11 is communicated with the first main valve working oil port A1. At the moment, the large cavity of the boom cylinder is filled with oil, the small cavity of the boom cylinder is filled with oil, and the boom descends.
And S22, starting the reversing valve by the controller, so that the reversing valve can communicate the large cavity with the small cavity. Meanwhile, the reversing valve is started, so that oil in the small cavity of the movable arm oil cylinder enters the large cavity of the movable arm oil cylinder, the oil pressure in the large cavity of the movable arm oil cylinder is improved, air is prevented from being separated out from oil liquid to cause burning of sealing elements, abnormal sound and cavitation of components, and the later-period operation and maintenance cost is reduced.
Preferably, in step S22, the controller receives the hydraulic signals in the large chamber and the small chamber, and controls the flow rate of the directional valve according to the pressure difference between the liquids in the large chamber and the small chamber, where the formula is: the flow rate Q = K (small chamber hydraulic pressure F1 — large chamber hydraulic pressure F2), where K is a flow rate coefficient. When the hydraulic control valve is used, the difference value between the small cavity hydraulic pressure F and the large cavity hydraulic pressure F is in direct proportion to the flow Q of the reversing valve, namely the larger the pressure difference between the small cavity and the large cavity is, the higher the flow Q of the reversing valve is, the speed of oil in the small cavity of the movable arm oil cylinder entering the large cavity of the movable arm oil cylinder is increased, and the damage time of air separation from the oil is reduced.
Preferably, in step S22, the time from when the controller activates the selector valve to when the small chamber hydraulic pressure F1 and the large chamber hydraulic pressure F2 are equal is 2 to 3S. When the movable arm oil cylinder is used, oil in the small cavity of the movable arm oil cylinder enters the large cavity of the movable arm oil cylinder in a short time, and the damage time of air separation from the oil is reduced.
Preferably, the boom raising system further includes a boom raising process, and the boom raising process includes the steps of:
s11, the controller starts the main pump and controls the valve core of the main valve to move, so that the first main valve oil inlet P11 is communicated with the first main valve working oil port A1, and the first main valve oil return port T11 is communicated with the second main valve working oil port B1. When the boom is required to ascend, a valve core of the main valve moves, the first main valve oil inlet P11 is communicated with the first main valve working oil port A1, and the first main valve oil return port T11 is communicated with the second main valve working oil port B1. At the moment, the small cavity of the boom cylinder is filled with oil, the large cavity of the boom cylinder is filled with oil, and the boom is lifted.
In conclusion, the beneficial effects of the invention are as follows: when the movable arm descends, the reversing valve is started, so that oil in the small cavity of the movable arm oil cylinder enters the large cavity of the movable arm oil cylinder, the oil pressure in the large cavity of the movable arm oil cylinder is improved, burning, abnormal sound and cavitation of components and parts caused by separation of air from oil are avoided, and later-period operation and maintenance cost is reduced.
Drawings
Fig. 1 is a schematic structural diagram of a boom hydraulic system of an excavator in embodiment 1 of the present invention;
FIG. 2 is a schematic diagram of a main valve in a hydraulic system of a boom of an excavator according to the present invention;
FIG. 3 is a schematic structural diagram of a differential directional control valve in a hydraulic system of a movable arm of an excavator;
fig. 4 is a schematic structural diagram of a boom hydraulic system of an excavator in embodiment 2 of the present invention.
In the figure: 1. a hydraulic oil tank; 2. a main pump; 3. a main valve; 4. a first pilot oil interface; 5. a second pilot oil interface; 6. a boom cylinder; 7. a diverter valve; 8. a holding valve; 9. a compensation valve; 10. a small-cavity hydraulic sensor; 11. a large-cavity hydraulic sensor.
Detailed Description
The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.
In the description of the present application, it is to be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present application and simplifying the description, but do not indicate or imply that the referred device or element must have a particular orientation, be constructed in a particular orientation, and be operated, and thus should not be construed as limiting the present application.
The terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless otherwise specified.
In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.
Embodiment 1, as shown in fig. 1 to 3, a boom hydraulic system of an excavator includes a hydraulic oil tank 1, a main pump 2, a boom cylinder 6, and a main valve 3, where the main valve 3 includes a first main valve oil inlet P11, a first main valve oil return port T11, a second main valve oil return port T12, a second main valve oil inlet P12, a first main valve working oil port a1, a second main valve working oil port B1, a third main valve working oil port C1, and a fourth main valve working oil port D1.
Specifically, the first main valve oil inlet P11 can be closed or communicated with one of the first main valve working oil port a1 and the second main valve working oil port B1; the first main valve oil return port T11 can be closed or communicated with one of the second main valve working oil port B1 and the first main valve working oil port a 1; the second main valve oil return port T12 can be closed or in communication with the third main valve working port C1; the second main valve oil inlet P12 can be closed or in communication with the fourth main valve working oil port D1. The second main valve oil inlet P12 is communicated with the main pump 2, the fourth main valve working oil port D1 is communicated with a compensation valve 9, the compensation valve 9 is communicated with the first main valve oil inlet P11, and the first main valve oil return port T11 and the second main valve oil return port T12 are communicated with the hydraulic oil tank 1. The first main valve working oil port A1 is communicated with a holding valve 8, the holding valve 8 is communicated with a small cavity oil inlet P31 of the movable arm oil cylinder 6, the second main valve working oil port B1 is communicated with a large cavity oil inlet P32 of the movable arm oil cylinder 6, a reversing valve 7 is connected between the small cavity oil inlet P31 and the large cavity oil inlet P32, and the reversing valve 7 can be closed or communicated with the large cavity and the small cavity. The holding valve 8 and the compensation valve 9 are of the prior art and will not be described in detail here.
Preferably, a small-chamber hydraulic sensor 10 is installed in the small chamber of boom cylinder 6, and a large-chamber hydraulic sensor 11 is installed in the large chamber of boom cylinder 6. When the hydraulic measuring device is used, the small cavity hydraulic sensor 10 and the large cavity hydraulic sensor 11 are used for measuring the hydraulic values of the small cavity and the large cavity of the movable arm oil cylinder 6, and reference is provided for subsequent decision making.
In the initial state, each port of the main valve 3 is in a closed position, and the boom cylinder 6 is also in an arbitrary stop position.
When the boom is required to be lifted, the spool of the main valve 3 moves, the first main valve oil inlet P11 is communicated with the first main valve working oil port a1, and the first main valve oil return port T11 is communicated with the second main valve working oil port B1. At this time, the small cavity of the boom cylinder 6 is filled with oil, and the large cavity of the boom cylinder 6 is filled with oil, so that the boom is lifted.
When the boom needs to be lowered, the valve core of the main valve 3 moves, the first main valve oil inlet P11 is communicated with the second main valve working oil port B1, and the first main valve oil return port T11 is communicated with the first main valve working oil port a 1. At the moment, the large cavity of the movable arm oil cylinder 6 is filled with oil, and the small cavity of the movable arm oil cylinder 6 is filled with oil, so that the movable arm descends; meanwhile, the reversing valve 7 is started, so that oil in the small cavity of the movable arm oil cylinder 6 enters the large cavity of the movable arm oil cylinder 6, the oil pressure in the large cavity of the movable arm oil cylinder 6 is improved, air is prevented from being separated out from oil to cause burning of a sealing element, abnormal sound and cavitation of components, and the later-period operation and maintenance cost is reduced.
The main valve 3 further includes a boom-up pilot oil port a1 and a boom-down pilot oil port b1, the boom-up pilot oil port a1 is communicated with a first pilot oil port 4, the boom-down pilot oil port b1 is communicated with a second pilot oil port 5, and specifically, the first pilot oil port 4 and the second pilot oil port 5 are connected with a pilot oil supply device, and the pilot oil supply device adopts the prior art, which is not described herein again. When the boom-up pilot oil port a1 obtains pilot oil, the first main valve oil inlet P11 is communicated with the first main valve working oil port a1, and the first main valve oil return port T11 is communicated with the second main valve working oil port B1; when the movable arm descends to the pilot oil port B1 to obtain pilot oil, the first main valve oil inlet P11 is communicated with the second main valve working oil port B1; the first main valve return port T11 communicates with the first main valve working port a 1. When the valve is used, the valve core of the main valve 3 is driven by pilot oil, the structure is compact, the service life is long, and the later-period operation and maintenance cost is reduced.
Preferably, the reversing valve 7 comprises a reversing valve oil inlet P2 and a reversing valve working oil port A2, and the reversing valve oil inlet P2 can be closed or communicated with the reversing valve working oil port A2. When the reversing valve is used, the reversing valve 7 adopts a two-position two-way valve, the structure is compact, the service life is long, and the later-period operation and maintenance cost is reduced.
The reversing valve 7 further comprises a reversing pilot oil port a2, and the reversing pilot oil port a2 is communicated with the second pilot oil port 5. When the reversing valve is used, the valve core of the reversing valve 7 is driven by pilot oil, the structure is compact, the service life is long, and the later-period operation and maintenance cost is reduced; meanwhile, when the second pilot oil port 5 supplies oil to the boom-lowering pilot oil port b1, oil is simultaneously supplied to the reversing pilot oil port a2, boom lowering and the reversing valve 7 are simultaneously performed, so that oil in the small cavity of the boom cylinder 6 enters the large cavity of the boom cylinder 6.
A control method of a boom hydraulic system according to embodiment 1, comprising a boom-up process including the steps of:
s11, the controller starts the main pump 2 and controls the valve core of the main valve 3 to move, such that the first main valve oil inlet P11 is communicated with the first main valve working oil port a1, and the first main valve oil return port T11 is communicated with the second main valve working oil port B1.
When the boom is required to be lifted, the spool of the main valve 3 moves, the first main valve oil inlet P11 is communicated with the first main valve working oil port a1, and the first main valve oil return port T11 is communicated with the second main valve working oil port B1. At this time, the small cavity of the boom cylinder 6 is filled with oil, and the large cavity of the boom cylinder 6 is filled with oil, so that the boom is lifted.
The method further comprises a movable arm descending process, wherein the movable arm descending process comprises the following steps:
s21, the controller starts the main pump 2 and controls the valve core of the main valve 3 to move, such that the first main valve oil inlet P11 is communicated with the second main valve working oil port B1, and the first main valve oil return port T11 is communicated with the first main valve working oil port a 1. When the boom needs to be lowered, the valve core of the main valve 3 moves, the first main valve oil inlet P11 is communicated with the second main valve working oil port B1, and the first main valve oil return port T11 is communicated with the first main valve working oil port a 1. At this time, the large cavity of the boom cylinder 6 is filled with oil, and the small cavity of the boom cylinder 6 is filled with oil, so that the boom descends.
S22, the controller starts the reversing valve 7 to enable the reversing valve 7 to communicate the large cavity with the small cavity. Meanwhile, the reversing valve 7 is started, so that oil in the small cavity of the movable arm oil cylinder 6 enters the large cavity of the movable arm oil cylinder 6, the oil pressure in the large cavity of the movable arm oil cylinder 6 is improved, air is prevented from being separated out from oil to cause burning of a sealing element, abnormal sound and cavitation of components, and the later-period operation and maintenance cost is reduced.
Specifically, the first main valve oil inlet P11 can be closed or communicated with one of the first main valve working oil port a1 and the second main valve working oil port B1; the first main valve oil return port T11 can be closed or communicated with one of the second main valve working oil port B1 and the first main valve working oil port a 1; the second main valve oil return port T12 can be closed or in communication with the third main valve working port C1; the second main valve oil inlet P12 can be closed or in communication with the fourth main valve working oil port D1. The second main valve oil inlet P12 is communicated with the main pump 2, the fourth main valve working oil port D1 is communicated with a compensation valve 9, the compensation valve 9 is communicated with the first main valve oil inlet P11, and the first main valve oil return port T11 and the second main valve oil return port T12 are communicated with the hydraulic oil tank 1. The first main valve working oil port A1 is communicated with a holding valve 8, the holding valve 8 is communicated with a small cavity oil inlet P31 of the movable arm oil cylinder 6, the second main valve working oil port B1 is communicated with a large cavity oil inlet P32 of the movable arm oil cylinder 6, a reversing valve 7 is connected between the small cavity oil inlet P31 and the large cavity oil inlet P32, and the reversing valve 7 can be closed or communicated with the large cavity and the small cavity. The holding valve 8 and the compensation valve 9 are of the prior art and will not be described in detail here.
Preferably, a small-chamber hydraulic sensor 10 is installed in the small chamber of boom cylinder 6, and a large-chamber hydraulic sensor 11 is installed in the large chamber of boom cylinder 6. When the hydraulic measuring device is used, the small cavity hydraulic sensor 10 and the large cavity hydraulic sensor 11 are used for measuring the hydraulic values of the small cavity and the large cavity of the movable arm oil cylinder 6, and reference is provided for subsequent decision making.
In the initial state, each port of the main valve 3 is in a closed position, and the boom cylinder 6 is also in an arbitrary stop position.
When the boom is required to be lifted, the spool of the main valve 3 moves, the first main valve oil inlet P11 is communicated with the first main valve working oil port a1, and the first main valve oil return port T11 is communicated with the second main valve working oil port B1. At this time, the small cavity of the boom cylinder 6 is filled with oil, and the large cavity of the boom cylinder 6 is filled with oil, so that the boom is lifted.
When the boom needs to be lowered, the valve core of the main valve 3 moves, the first main valve oil inlet P11 is communicated with the second main valve working oil port B1, and the first main valve oil return port T11 is communicated with the first main valve working oil port a 1. At the moment, the large cavity of the movable arm oil cylinder 6 is filled with oil, and the small cavity of the movable arm oil cylinder 6 is filled with oil, so that the movable arm descends; meanwhile, the reversing valve 7 is started, so that oil in the small cavity of the movable arm oil cylinder 6 enters the large cavity of the movable arm oil cylinder 6, the oil pressure in the large cavity of the movable arm oil cylinder 6 is improved, air is prevented from being separated out from oil to cause burning of a sealing element, abnormal sound and cavitation of components, and the later-period operation and maintenance cost is reduced.
The main valve 3 further includes a boom-up pilot oil port a1 and a boom-down pilot oil port b1, the boom-up pilot oil port a1 is communicated with a first pilot oil port 4, the boom-down pilot oil port b1 is communicated with a second pilot oil port 5, and specifically, the first pilot oil port 4 and the second pilot oil port 5 are connected with a pilot oil supply device, and the pilot oil supply device adopts the prior art, which is not described herein again. When the boom-up pilot oil port a1 obtains pilot oil, the first main valve oil inlet P11 is communicated with the first main valve working oil port a1, and the first main valve oil return port T11 is communicated with the second main valve working oil port B1; when the movable arm descends to the pilot oil port B1 to obtain pilot oil, the first main valve oil inlet P11 is communicated with the second main valve working oil port B1; the first main valve return port T11 communicates with the first main valve working port a 1. When the valve is used, the valve core of the main valve 3 is driven by pilot oil, the structure is compact, the service life is long, and the later-period operation and maintenance cost is reduced.
Preferably, the reversing valve 7 comprises an electromagnetic ball valve. When in use, the flow of the reversing valve 7 is convenient to adjust.
A control method of a boom hydraulic system according to embodiment 2, comprising a boom-up process including the steps of:
s11, the controller starts the main pump 2 and controls the valve core of the main valve 3 to move, such that the first main valve oil inlet P11 is communicated with the first main valve working oil port a1, and the first main valve oil return port T11 is communicated with the second main valve working oil port B1.
When the boom is required to be lifted, the spool of the main valve 3 moves, the first main valve oil inlet P11 is communicated with the first main valve working oil port a1, and the first main valve oil return port T11 is communicated with the second main valve working oil port B1. At this time, the small cavity of the boom cylinder 6 is filled with oil, and the large cavity of the boom cylinder 6 is filled with oil, so that the boom is lifted.
The method further comprises a movable arm descending process, wherein the movable arm descending process comprises the following steps:
s21, the controller starts the main pump 2 and controls the valve core of the main valve 3 to move, such that the first main valve oil inlet P11 is communicated with the second main valve working oil port B1, and the first main valve oil return port T11 is communicated with the first main valve working oil port a 1.
When the boom needs to be lowered, the valve core of the main valve 3 moves, the first main valve oil inlet P11 is communicated with the second main valve working oil port B1, and the first main valve oil return port T11 is communicated with the first main valve working oil port a 1. At this time, the large cavity of the boom cylinder 6 is filled with oil, and the small cavity of the boom cylinder 6 is filled with oil, so that the boom descends.
S22, the controller starts the reversing valve 7 to enable the reversing valve 7 to communicate the large cavity with the small cavity. Preferably, the controller receives hydraulic signals in the large cavity and the small cavity, and controls the flow of the reversing valve 7 according to the pressure difference of the liquid in the large cavity and the small cavity, and the formula is as follows: the flow rate Q = K (small chamber hydraulic pressure F1 — large chamber hydraulic pressure F2), where K is a flow rate coefficient.
When the hydraulic control system is used, the difference value between the small cavity hydraulic pressure F1 and the large cavity hydraulic pressure F2 is in direct proportion to the flow Q of the reversing valve 7, namely the larger the pressure difference between the small cavity and the large cavity is, the higher the flow Q of the reversing valve 7 is, the speed of oil in the small cavity of the boom oil cylinder 6 entering the large cavity of the boom oil cylinder 6 is increased, and the damage time of air separation from the oil is reduced.
Further, the time from the activation of the controller by the direction valve 7 to the time when the small chamber hydraulic pressure F1 is equal to the large chamber hydraulic pressure F2 is 2 to 3S, preferably, 2, 2.5 or 3S.
When the movable arm oil cylinder is used, oil in the small cavity of the movable arm oil cylinder 6 enters the large cavity of the movable arm oil cylinder 6 in a short time, and the harm time of air separation from the oil is reduced.
Meanwhile, the reversing valve 7 is started, so that oil in the small cavity of the movable arm oil cylinder 6 enters the large cavity of the movable arm oil cylinder 6, the oil pressure in the large cavity of the movable arm oil cylinder 6 is improved, air is prevented from being separated out from oil to cause burning of a sealing element, abnormal sound and cavitation of components, and the later-period operation and maintenance cost is reduced.
The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and substitutions can be made without departing from the technical principle of the present invention, and these modifications and substitutions should also be regarded as the protection scope of the present invention.
Claims (10)
1. The excavator boom hydraulic system comprises a hydraulic oil tank (1), a main pump (2), a boom oil cylinder (6) and a main valve (3), wherein the main valve (3) comprises a first main valve oil inlet P11, a first main valve oil return port T11, a first main valve working oil port A1 and a second main valve working oil port B1, and the first main valve oil inlet P11 can be closed or communicated with one of the first main valve working oil port A1 and the second main valve working oil port B1; the first main valve oil return port T11 can be closed or communicated with one of the second main valve working oil port B1 and the first main valve working oil port a 1; the first main valve working oil port A1 is communicated with a small cavity oil inlet P31 of a movable arm oil cylinder (6), the second main valve working oil port B1 is communicated with a large cavity oil inlet P32 of the movable arm oil cylinder (6), a reversing valve (7) is connected between the small cavity oil inlet P31 and the large cavity oil inlet P32, and the reversing valve (7) can close or communicate the large cavity and the small cavity.
2. The excavator boom hydraulic system as claimed in claim 1, wherein the main valve (3) further comprises a boom-up pilot oil port a1 and a boom-down pilot oil port B1, and when the boom-up pilot oil port a1 obtains pilot oil, the first main valve oil inlet P11 communicates with the first main valve working port a1, and the first main valve oil return T11 communicates with the second main valve working port B1; when the movable arm descends to the pilot oil port B1 to obtain pilot oil, the first main valve oil inlet P11 is communicated with the second main valve working oil port B1; the first main valve return port T11 is not in communication with the first main valve working port.
3. The excavator boom hydraulic system as claimed in claim 2, wherein the reversing valve (7) comprises a reversing valve oil inlet P2 and a reversing valve working oil port a2, and the reversing valve oil inlet P2 can be closed or communicated with the reversing valve working oil port a 2.
4. The hydraulic system for the boom of the excavator according to claim 3, wherein the boom-up pilot oil port a1 is communicated with the first pilot oil port (4), the boom-down pilot oil port b1 is communicated with the second pilot oil port (5), and the reversing valve (7) further comprises a reversing pilot oil port a2, and the reversing pilot oil port a2 is communicated with the second pilot oil port (5).
5. The excavator boom hydraulic system as claimed in claim 1, characterized in that the reversing valve (7) comprises an electromagnetic ball valve.
6. The excavator boom hydraulic system according to claim 5, wherein a small chamber hydraulic sensor (10) is installed in a small chamber of the boom cylinder (6), and a large chamber hydraulic sensor (11) is installed in a large chamber of the boom cylinder (6).
7. The control method of the excavator boom hydraulic system as claimed in claim 1, comprising a boom-down process, the boom-down process comprising the steps of:
s21, the controller starts the main pump (2) and controls the valve core of the main valve (3) to move, so that the first main valve oil inlet P11 is communicated with the second main valve working oil port B1, and the first main valve oil return port T11 is communicated with the first main valve working oil port A1;
and S22, the controller starts the reversing valve (7) to enable the reversing valve (7) to be communicated with the large cavity and the small cavity.
8. The control method according to claim 7, wherein in step S22, the controller receives the hydraulic signals in the large chamber and the small chamber, and controls the flow rate of the directional valve (7) according to the pressure difference between the liquids in the large chamber and the small chamber by the formula: the flow rate Q = K (small chamber hydraulic pressure F1 — large chamber hydraulic pressure F2), where K is a flow rate coefficient.
9. The control method according to claim 8, characterized in that in step S22, the time from when the controller activates the selector valve (7) to when the small chamber hydraulic pressure F1 and the large chamber hydraulic pressure F2 are equal is 2-3S.
10. The control method according to claim 7, further comprising a boom-up process, the boom-up process including the steps of:
s11, the controller starts the main pump (2) and controls the valve core of the main valve (3) to move, so that the first main valve oil inlet P11 is communicated with the first main valve working oil port A1, and the first main valve oil return port T11 is communicated with the second main valve working oil port B1.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202110720914.5A CN113323070B (en) | 2021-06-28 | 2021-06-28 | Excavator movable arm hydraulic system and control method thereof |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202110720914.5A CN113323070B (en) | 2021-06-28 | 2021-06-28 | Excavator movable arm hydraulic system and control method thereof |
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| CN113323070A CN113323070A (en) | 2021-08-31 |
| CN113323070B true CN113323070B (en) | 2022-03-25 |
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Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4223389C2 (en) * | 1992-07-16 | 2001-01-04 | Mannesmann Rexroth Ag | Control arrangement for at least one hydraulic consumer |
| CN102094434B (en) * | 2011-01-11 | 2012-05-30 | 浙江大学 | System for differential recovery of potential energy of boom of oil liquid hybrid power excavating machine |
| CN102518156B (en) * | 2012-01-04 | 2014-04-16 | 江苏柳工机械有限公司 | System for accurately controlling the rotation of excavation end of loader digger |
| CN104929170B (en) * | 2015-05-27 | 2017-08-25 | 徐工集团工程机械股份有限公司科技分公司 | A kind of loading machine lifts swing arm energy conserving system |
| CN109183870B (en) * | 2018-09-19 | 2020-09-11 | 柳州柳工挖掘机有限公司 | Hydraulic control system and lifting control method for movable arm of excavator |
| CN111473008A (en) * | 2020-05-18 | 2020-07-31 | 三一重机有限公司 | Excavator boom cylinder control system and control method |
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Address after: 266500 No. 75 East Huanghe Road, Huangdao District, Qingdao City, Shandong Province Patentee after: Lovol Heavy Industry Group Co.,Ltd. Address before: 266500 No. 75 East Huanghe Road, Huangdao District, Qingdao City, Shandong Province Patentee before: LOVOL Engineering Machinery Group Co.,Ltd. |
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Effective date of registration: 20231205 Address after: Room 3-3052, No. 3 Dagongdao Road, Huangdao District, Qingdao City, Shandong Province, 266000 Patentee after: Weichai (Qingdao) Smart Heavy Industry Co.,Ltd. Address before: 266500 No. 75 East Huanghe Road, Huangdao District, Qingdao City, Shandong Province Patentee before: Lovol Heavy Industry Group Co.,Ltd. |