CN112796366A - Loader hydraulic system and loader - Google Patents
Loader hydraulic system and loader Download PDFInfo
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- CN112796366A CN112796366A CN202110119347.8A CN202110119347A CN112796366A CN 112796366 A CN112796366 A CN 112796366A CN 202110119347 A CN202110119347 A CN 202110119347A CN 112796366 A CN112796366 A CN 112796366A
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- 238000001514 detection method Methods 0.000 claims abstract description 45
- 239000003921 oil Substances 0.000 description 215
- 238000004134 energy conservation Methods 0.000 description 8
- 230000001133 acceleration Effects 0.000 description 5
- 230000009471 action Effects 0.000 description 5
- 238000007599 discharging Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000000446 fuel Substances 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000003044 adaptive effect Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000009412 basement excavation Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000010720 hydraulic oil Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 230000009897 systematic 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
- E02F9/22—Hydraulic or pneumatic drives
-
- 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
- E02F9/225—Control of steering, e.g. for hydraulic motors driving the vehicle tracks
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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
- E02F9/2264—Arrangements or adaptations of elements for hydraulic drives
- E02F9/2267—Valves or distributors
-
- 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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- 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 loader hydraulic system and a loader, and relates to the technical field of engineering machinery. The system comprises an oil tank, a steering pump and a working pump which are communicated with the oil tank, a steering gear connected with the steering pump, and a multi-way valve group connected with the working pump, wherein a P port of a priority valve of the system is connected with the steering pump, and a CF port of the system is connected with an oil inlet of the steering gear; the port P of the reversing valve is communicated with the port EF of the priority valve, the port PS is connected with the oil tank, and the port PW is communicated with the oil outlet of the working pump; the pilot valve group is connected with the reversing valve, and a working oil port of the pilot valve group is communicated with a pilot end of the multi-way valve group; the port P of the pilot valve group is communicated with the working pump, and the port T is communicated with the oil tank; the first detection piece is arranged between the pilot valve group and the reversing valve and can detect the output pressure of the pilot valve group; the second detecting member can detect the rotating speed of the engine, and the reversing valve can receive signals of the two detecting members to reverse to enable the EF port of the priority valve and the PW port of the reversing valve to be communicated. The system can realize flow merging and flow dividing under the control of pressure and rotating speed.
Description
Technical Field
The invention relates to the technical field of engineering machinery, in particular to a loader hydraulic system and a loader.
Background
The loader is one of the most commonly used engineering machines, and is mainly used for shoveling work and loading work, and in view of the above work requirements, the working device of the loader needs to be subjected to bucket collection, lifting, unloading and descending, and the whole machine needs to be frequently subjected to left and right steering, and all the actions are realized through the control of a loader hydraulic system. In general, a hydraulic system of a loader is composed of a work device hydraulic system and a steering system, in which a work pump separately supplies a bucket cylinder and a lift cylinder in the work device hydraulic system, and a steering pump separately supplies a steering cylinder.
At present, more and more loaders are used for tunnel construction on a plateau, and the steering and working confluence of a loader hydraulic system in the prior art is generally in a mode of directly merging an EF port of a steering priority valve with a working P port, and the confluence of the hydraulic system occurs at various rotating speeds of an engine. However, because the altitude in the plateau area is high and the oxygen is relatively thin, the engine with the turbocharger has poor supercharging effect when the rotating speed of the engine is low under the working condition of the plateau, so that the low-speed loaded acceleration performance of the engine is poor, and the engine is easy to stall when a hydraulic system works at low rotating speed in a confluence manner; meanwhile, under the condition of any rotating speed, the uniform confluence can cause that a large amount of oil overflows when the load is used for shoveling, and the system cannot save energy.
Disclosure of Invention
The invention aims to provide a loader hydraulic system and a loader, which can improve the loaded acceleration performance of an engine, prevent the engine from stalling, reduce the load at low speed of the engine to realize energy conservation, and simultaneously realize energy conservation under the excavation working condition.
In order to achieve the purpose, the invention adopts the following technical scheme:
a loader hydraulic system comprising: the oil tank, with turn to the pump of oil tank intercommunication, with turn to the steering gear that the pump is connected, with the working pump of oil tank intercommunication and with the multichannel valves that the working pump is connected still include:
the priority valve comprises an oil inlet P port, an oil outlet CF port and an oil outlet EF port, the oil inlet P port of the priority valve is connected with the steering pump, and the oil outlet CF port is connected with the oil inlet of the steering gear;
the reversing valve comprises an oil inlet P port, an oil outlet PS port and an oil outlet PW port, the oil inlet P port of the reversing valve is communicated with an oil outlet EF port of the priority valve, the oil outlet PS port is communicated with the oil tank, and the oil outlet PW port is communicated with an oil outlet of the working pump;
the pilot valve group is connected with the reversing valve and communicated with a working oil port of the pilot valve group and a pilot end of the multi-way valve group, a P port of the pilot valve group is communicated with the working pump, and a T port of the pilot valve group is communicated with the oil tank;
the first detection piece is arranged between the pilot valve group and the reversing valve and is used for detecting the output pressure of the pilot valve group;
the second detection piece is used for detecting the engine speed of the loader, and the reversing valve can receive control signals of the first detection piece and the second detection piece to reverse, so that an oil outlet EF port of the priority valve is communicated with an oil outlet PW port of the reversing valve.
Optionally, the loader hydraulic system further comprises an electromagnetic valve, an oil inlet P of the electromagnetic valve is connected with the multi-way valve bank, a working oil port is communicated with a pilot end of the reversing valve, and an oil return port T is communicated with the oil tank; the first detection piece is arranged between the pilot valve group and the electromagnetic valve, and the electromagnetic valve can receive control signals of the first detection piece and the second detection piece to be conducted so as to enable the reversing valve to be reversed.
Optionally, the pilot valve group comprises a boom pilot handle, a rotating bucket pilot handle and a side dump pilot handle, the boom pilot handle is connected with an a2 oil port and a b2 oil port of a pilot end of a boom multi-way valve of the multi-way valve group, the rotating bucket pilot handle is connected with an a1 oil port and a b1 oil port of the pilot end of the rotating bucket multi-way valve of the multi-way valve group, the side dump pilot handle is connected with an a3 oil port and a b3 oil port of the pilot end of the side dump multi-way valve of the multi-way valve group, and the a2 oil port, the b1 oil port and the b3 oil port are all communicated with a P port of the electromagnetic valve through a shuttle valve group.
Optionally, the shuttle valve group includes a first shuttle valve and a second shuttle valve, the a2 oil port and the b3 oil port are respectively connected with two oil inlets of the first shuttle valve, the oil outlet of the first shuttle valve and the b1 oil port are respectively connected with two oil inlets of the second shuttle valve, the oil outlet of the second shuttle valve is connected with the electromagnetic valve, and the first detection element is disposed between the oil outlet of the second shuttle valve and the P port of the electromagnetic valve.
Optionally, a connection pipeline between the working oil port of the electromagnetic valve and the pilot end of the reversing valve is provided with a throttle hole.
Optionally, the loader hydraulic system further includes an oil return filter element, the oil return filter element is communicated with the oil tank, and an oil outlet PS port of the reversing valve, an oil return port T port of the electromagnetic valve, and an oil return port of the pilot valve group are all communicated with the oil return filter element.
Optionally, the first detection member is a pressure switch.
Optionally, the second detection member is a rotation speed sensor.
Optionally, the directional valve is a pilot operated directional valve.
A loader comprises the loader hydraulic system.
The invention has the beneficial effects that: the loader hydraulic system provided by the invention can supply oil to a steering gear through a steering pump, can supply oil to a pilot valve group through a working pump, can detect the output pressure of the pilot valve group through a first detection piece, can detect the rotating speed of an engine through a second detection piece, and when a reversing valve cannot receive a control signal of the first detection piece and the second detection piece or can only receive one control signal of the first detection piece and the second detection piece, the reversing valve does not reverse, at the moment, oil at an oil outlet EF port of a priority valve directly returns to an oil tank through an oil outlet PS port of the reversing valve after passing through an oil inlet P port of the reversing valve, and the oil of the steering pump and the working pump does not merge; when the reversing valve can receive the control signals of the first detection piece and the second detection piece at the same time, the reversing valve reverses, an oil outlet EF port of the priority valve is communicated with an oil outlet PW port of the reversing valve, oil of the oil outlet EF port of the priority valve is converged to an oil outlet of the working pump through an oil outlet PW port of the reversing valve, and therefore confluence of the oil of the steering pump and the oil of the working pump is achieved. The loader hydraulic system can realize confluence and diversion under the control of the output pressure of the pilot valve group and the rotating speed of the engine, can improve the loaded acceleration performance of the engine, prevent the engine from stalling, can reduce the load to realize energy conservation when the engine is at low speed, and can realize energy conservation when the engine is in a digging working condition; meanwhile, the numerical values of the output pressure of the pilot valve group and the rotating speed of the engine can be set adaptively, so that the application range of the hydraulic system of the loader is wider.
Drawings
Fig. 1 is a schematic structural diagram of a hydraulic system of a loader according to an embodiment of the present invention.
In the figure:
100-an engine;
1-an oil tank; 2-a steering pump; 3-a diverter; 4-a working pump; 5-a multi-way valve bank; 6-a priority valve; 7-a reversing valve; 8-an electromagnetic valve; 9-a first detection member; 10-a second detection member; 11-boom pilot handle; 12-rotating bucket pilot handle; 13-side dump pilot handle; 14-a first shuttle valve; 15-a second shuttle valve; 16-orifice; 17-an oil return filter element; 18-a pilot oil supply valve; 19-an oil filter; 20-a steering oil cylinder; 21-a boom cylinder; 22-rotating bucket oil cylinder; 23-side dump cylinder.
Detailed Description
In order to make the technical problems solved, technical solutions adopted and technical effects achieved by the present invention clearer, the technical solutions of the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, removably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.
The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.
As shown in fig. 1, the loader hydraulic system comprises an oil tank 1, a steering pump 2 communicated with the oil tank 1, a steering gear 3 connected with the steering pump 2, a working pump 4 communicated with the oil tank 1, a multi-way valve group 5 connected with the working pump 4, a priority valve 6, a reversing valve 7, a pilot valve group, a first detection part 9 and a second detection part 10, wherein the priority valve 6 comprises an oil inlet P, an oil outlet CF and an oil outlet EF, the oil inlet P of the priority valve 6 is connected with the steering pump 2, and the oil outlet CF is connected with an oil inlet of the steering gear 3; the reversing valve 7 comprises an oil inlet P port, an oil outlet PS port and an oil outlet PW port, the oil inlet P port of the reversing valve 7 is communicated with an oil outlet EF port of the priority valve 6, the oil outlet PS port is communicated with the oil tank 1, and the oil outlet PW port is communicated with an oil outlet of the working pump 4; the pilot valve group is connected with the reversing valve 7, a working oil port of the pilot valve group is communicated with a pilot end of the multi-way valve group 5, a port P of the pilot valve group is communicated with the working pump 4, and a port T is communicated with the oil tank 1; the first detection piece 9 is arranged between the pilot valve group and the reversing valve 7 and is used for detecting the output pressure of the pilot valve group; the second detecting member 10 is used for detecting the rotation speed of the engine 100 of the loader, and the reversing valve 7 can receive the control signals of the first detecting member 9 and the second detecting member 10 to reverse, so that the oil outlet port EF of the priority valve 6 and the oil outlet port PW of the reversing valve 7 are communicated. It can be understood that the hydraulic system of the vehicle can supply oil to the steering gear 3 through the steering pump 2, can supply oil to the pilot valve group through the working pump 4, can detect the output pressure of the pilot valve group through the first detecting part 9, can detect the rotation speed of the engine 100 through the second detecting part 10, when the reversing valve 7 cannot receive the control signal of the first detecting part 9 and the second detecting part 10, or the reversing valve 7 can only receive one of the control signals, the reversing valve 7 does not reverse, at this time, the oil at the oil outlet EF port of the priority valve 6 directly returns to the oil tank 1 through the oil outlet PS port of the reversing valve 7 after passing through the oil inlet P port of the reversing valve 7, and the oil of the steering pump 2 and the working pump 4 do not merge; when the reversing valve 7 can receive control signals of the first detection part 9 and the second detection part 10 at the same time, the reversing valve 7 reverses, an oil outlet EF port of the priority valve 6 is communicated with an oil outlet PW port of the reversing valve 7, oil at the oil outlet EF port of the priority valve 6 is converged to an oil outlet P port of the working pump 4 through an oil outlet PW port of the reversing valve 7, and therefore confluence of the oil of the steering pump 2 and the oil of the working pump 4 is achieved. The loader hydraulic system can realize confluence and diversion under the control of the output pressure of the pilot valve group and the rotating speed of the engine 100, can improve the loaded acceleration performance of the engine 100, prevent the engine 100 from stalling, can reduce the load to realize energy conservation when the engine 100 is at a low speed, and can realize energy conservation when the engine is in a digging working condition; meanwhile, the output pressure of the pilot valve group and the rotating speed of the engine 100 can be set in an adaptive manner, so that the application range of the hydraulic system of the loader is wider.
Optionally, the loader hydraulic system further comprises an electromagnetic valve 8, an oil inlet P of the electromagnetic valve 8 is connected with the multi-way valve group 5, a working oil port is communicated with a pilot end of the reversing valve 7, and an oil return port T is communicated with the oil tank 1; the first detection member 9 is disposed between the pilot valve group and the electromagnetic valve 8, and the electromagnetic valve 8 can receive control signals of the first detection member 9 and the second detection member 10 to conduct to reverse the reversing valve 7. Specifically, an a2 oil port, a b1 oil port and a b3 oil port of the multi-way valve group 5 are all connected with a P port of the solenoid valve 8; this loader hydraulic system still includes the control unit, solenoid valve 8, first detection piece 9 and second detection piece 10 all are connected with the control unit electricity, after the control unit received the control signal of first detection piece 9 and second detection piece 10 simultaneously, send the signal of telecommunication for solenoid valve 8, control solenoid valve 8 has electric conduction, the pressure fluid of 5 outputs of multichannel valves can enter into the guide end of switching-over valve 7 through solenoid valve 8 and make the switching-over valve 7 switching-over, the oil-out EF mouth of priority valve 6 and the oil-out PW mouth of switching-over valve 7 switch on this moment. In this embodiment, the reversing valve 7 is a pilot operated reversing valve, and in other embodiments, a solenoid reversing valve may be used instead of the solenoid valve 8 and the pilot operated reversing valve.
In this embodiment, the first detecting element 9 is provided with a preset pressure, the second detecting element 10 is provided with a first preset rotating speed, when the pressure detected by the first detecting element 9 reaches the preset pressure, a first signal is sent to the control unit, when the second detecting element 10 detects that the rotating speed of the engine 100 reaches the first preset rotating speed, a second signal is sent to the control unit, the control unit receives the first signal and the second signal and then controls the electromagnetic valve 8 to be electrically conducted, so that the reversing valve 7 is reversed, the oil outlet EF port of the priority valve 6 is conducted with the oil outlet PW port of the reversing valve 7, the oil in the oil outlet EF port of the priority valve 6 is merged to the oil outlet P port of the working pump 4 through the oil outlet PW port of the reversing valve 7, and merging of the oil in the steering pump 2 and the working pump 4 is achieved. Specific values of the preset pressure and the first preset rotating speed are not limited herein, and can be selected according to different adaptability of actual use requirements.
In this embodiment, the loader hydraulic system further includes a steering cylinder 20, the steering cylinder 20 is connected to the steering gear 3, and the steering cylinder 20 can be controlled by the steering gear 3 to steer. The specific structures and operation principles of the steering gear 3, the priority valve 6 and the steering cylinder 20 are known in the art and will not be described in detail herein.
Specifically, the first detection member 9 is a pressure switch; the second detecting member 10 is a rotation speed sensor. In the present embodiment, the engine 100 is connected to the steering pump 2, and a rotation speed sensor is provided on the engine 100 to detect the rotation speed of the engine 100. In other embodiments, the first detecting member 9 and the second detecting member 10 may have other structures.
Optionally, the pilot valve group comprises a boom pilot handle 11, a rotating bucket pilot handle 12 and a side dump pilot handle 13 which are connected with the working pump 4 and the oil tank 1, the boom pilot handle 11 is connected with an a2 oil port and a b2 oil port of a pilot end of a boom multi-way valve of the multi-way valve group 5, the rotating bucket pilot handle 12 is connected with an a1 oil port and a b1 oil port of the pilot end of the rotating bucket multi-way valve of the multi-way valve group 5, the side dump pilot handle 13 is connected with an a3 oil port and a b3 oil port of the pilot end of the side dump multi-way valve of the multi-way valve group 5, and the a2 oil port, the b1 oil port and the b3 oil port are all communicated with a port P of the. In the embodiment, oil inlets of a movable arm pilot handle 11, a rotating bucket pilot handle 12 and a side dump pilot handle 13 are all communicated with an oil outlet P of a working pump 4, and oil return ports are all communicated with an oil tank 1; the hydraulic system of the loader further comprises a movable arm oil cylinder 21, a rotary bucket oil cylinder 22 and a side dumping oil cylinder 23, wherein the movable arm oil cylinder 21 is connected with an A2 oil port and a B2 oil port of the movable arm multi-way valve, the rotary bucket oil cylinder 22 is connected with an A1 oil port and a B1 oil port of the rotary bucket multi-way valve, and the side dumping oil cylinder 23 is connected with an A3 oil port and a B3 oil port of the side dumping multi-way valve. It can be understood that when the working pump 4 works, oil is sucked from the oil tank 1 and flows to the oil inlet of the multi-way valve group 5 through the oil outlet P of the working pump 4, and if the boom pilot handle 11, the rotating bucket pilot handle 12 and the side dump pilot handle 13 have no action indication, hydraulic oil flows back to the oil tank 1 through the overflow valve in the multi-way valve group 5. When the rotating bucket pilot handle 12 acts, oil flows out from the oil outlet P of the working pump 4 and then enters the multi-way valve group 5, so that the rotating bucket multi-way valve of the multi-way valve group 5 can be pushed to move, the oil can flow into a rod cavity or a rodless cavity of the rotating bucket oil cylinder 22, the rotating bucket oil cylinder 22 is made to move, and then a connecting rod mechanism of the loader can be driven to enable a bucket of the loader to work. The working principle of the boom pilot handle 11 and the side dump pilot handle 13 is the same as above, and the detailed working processes of the three handles are all the prior art, and are not described again here.
Optionally, the shuttle valve group comprises a first shuttle valve 14 and a second shuttle valve 15, an a2 oil port and a b3 oil port are respectively connected with two oil inlets of the first shuttle valve 14, an oil outlet of the first shuttle valve 14 and a b1 oil port are respectively connected with two oil inlets of the second shuttle valve 15, an oil outlet of the second shuttle valve 15 is connected with the solenoid valve 8, and the first detection element 9 is arranged between the oil outlet of the second shuttle valve 15 and the port P of the solenoid valve 8. It can be understood that, in the use process of the loader, generally speaking, the boom pilot handle 11, the rotating bucket pilot handle 12 and the side dump pilot handle 13 only have one action, when only one action is performed, the shuttle valve group outputs pressure oil, and the pressure switch can detect whether the output pressure reaches the preset pressure; when two or three of the boom pilot handle 11, the swing bucket pilot handle 12, and the side dump pilot handle 13 are simultaneously operated, the output pressures of the two or three can be compared by the first shuttle valve 14 and the second shuttle valve 15, and the maximum pressure is output as the output pressure of the pilot valve group. In this embodiment, when the side dump pilot handle 13 is completely pushed to the right position, the boom pilot handle 11 and the swing bucket pilot handle 12 cannot operate, and only when the side dump pilot handle 13 is not completely pushed to the right position, the boom pilot handle 11 and the swing bucket pilot handle 12 can operate, and specifically, the operation relationship between the three handles can be adaptively adjusted according to actual use requirements.
Optionally, a throttle 16 is arranged on a connection pipeline between the working oil port of the electromagnetic valve 8 and the pilot end of the reversing valve 7. It can be understood that, when the output pressure of the pilot valve group reaches the preset pressure, the pressure switch is closed to output a first signal to the control unit, when the rotating speed of the engine 100 reaches the first preset rotating speed, the rotating speed sensor can output a second signal to the control unit, the control unit receives the two signals and then controls the electromagnetic valve 8 to be electrically conducted, the oil output by the pilot valve group enters the reversing valve 7 from the pilot end through the orifice 16 after passing through the electromagnetic valve 8 to reverse the reversing valve 7, so that the oil at the oil outlet EF port of the priority valve 6 can be merged to the oil outlet P port of the working pump 4 through the oil outlet PW port of the reversing valve 7, the systematic confluence is realized, and the confluence and shunting stability of the hydraulic system can be ensured through the orifice 16.
Optionally, the loader hydraulic system further includes an oil return filter element 17, the oil return filter element 17 is communicated with the oil tank 1, and an oil outlet PS of the reversing valve 7, an oil return port T of the solenoid valve 8, and an oil return port of the pilot valve group are all communicated with the oil return filter element 17. It can be understood that the return oil of the loader hydraulic system can be filtered by the return oil filter element 17, so that impurities can be prevented from entering the oil tank 1. In other embodiments, other structures such as a filter may be used instead of the oil return filter element 17.
Specifically, a pilot oil source valve 18 and an oil filter 19 which are connected with each other are further arranged between the working pump 4 and the pilot valve group, an oil inlet of the pilot oil source valve 18 is communicated with the working pump 4, an oil return port is communicated with the oil return filter element 17, and the oil filter 19 is communicated with an oil outlet of the pilot oil source valve 18. It can be understood that the pilot oil path can be controlled by the pilot oil source valve 18, so that the operation safety is ensured; the oil entering the pilot valve group can be filtered through the oil filter 19, and the entering of impurities is avoided. The detailed structure and principle of the pilot oil source valve 18 are already known in the art, and will not be described herein.
In the hydraulic system of the loader provided in this embodiment, when the rotation speed of the engine 100 is lower than the first preset rotation speed and the steering gear 3 does not work, the oil output by the steering pump 2 enters the oil inlet P of the hydraulic control directional control valve through the oil outlet EF of the priority valve 6, and then returns to the oil tank 1 through the oil outlet PS, and the oil of the steering pump 2 and the oil of the working pump 4 do not merge. When the rotating speed of the engine 100 rises to a first preset rotating speed, the rotating speed sensor outputs a second signal, if the boom pilot handle 11 is operated to lift the boom or the rotating bucket pilot handle 12 is operated to unload materials or the side unloading pilot handle 13 is operated to unload materials at the moment, the output pilot pressure can be compared through the shuttle valve group, when the preset pressure is reached, the pressure switch is closed to output a first signal, when the control unit receives the two signals simultaneously, the control electromagnetic valve 8 is electrified, and pilot oil enters the hydraulic control reversing valve through the throttling hole 16 after passing through the electromagnetic valve 8 to reverse the hydraulic control reversing valve, so that the oil at the oil outlet EF port of the priority valve 6 is converged to the oil outlet P port of the working pump 4 through the oil outlet PW port of the hydraulic control reversing valve, and the confluence of the system is realized. After the system is merged, if the rotation speed of the engine 100 is reduced to a second preset rotation speed (the second preset rotation speed is lower than the first preset rotation speed), the rotation speed sensor does not output a second signal or does not operate the boom pilot handle 11, the rotating bucket pilot handle 12 and the side dump pilot handle 13, that is, does not send out a first signal, the electromagnetic valve 8 is not powered, and at this time, the steering pump 2 and the working pump 4 of the system are not merged. The specific value of the second preset rotation speed is not limited herein, and can be adaptively selected according to the actual use requirement and the value of the first preset rotation speed.
In this embodiment, the multi-way valve group 5 is a pilot multi-way valve group, and the first preset rotation speed and the second preset rotation speed of the engine 100 are both preset in the control unit. In other embodiments, the electronic multi-way valve set can be controlled by an electric signal, and the mechanical multi-way valve set can be controlled by an output signal of a travel switch or a proximity switch. Meanwhile, the input pressure of the pressure switch in the embodiment adopts the pilot output pressure of movable arm lifting, side dumping discharging and rotary bucket discharging. In other embodiments, other output pressures of the pilot valve group may be selected, and are not limited herein.
The embodiment also provides a loader which comprises the loader hydraulic system. The loader hydraulic system can improve the loaded acceleration performance of the engine 100, prevent the engine 100 from stalling, is suitable for plateau working conditions, and has better dynamic performance under the plain working conditions; when the loader is in a shoveling working condition, the operation of collecting the bucket and slightly lifting the movable arm is needed, at the moment, a large amount of oil is not needed for the bucket and the movable arm, the system is not combined, and the energy conservation can be realized; when the engine 100 is at a low speed, fuel economy is poor, and at the moment, the fuel is not combined, so that load can be reduced, and energy conservation can be realized; in addition, confluence and shunting of the steering pump 2 and the working pump 4 can be automatically realized according to pressure and rotating speed signals, the lifting speed of the movable arm can be increased through confluence, and confluence or non-confluence can be selected according to working condition adaptability in other actions, so that the performance of the loader can be improved.
It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.
Claims (10)
1. A loader hydraulic system, comprising: oil tank (1), with turn to pump (2) of oil tank (1) intercommunication, with turn to steering gear (3) that pump (2) are connected, with working pump (4) of oil tank (1) intercommunication and with multichannel valves (5) that working pump (4) are connected still include:
the priority valve (6) comprises an oil inlet P port, an oil outlet CF port and an oil outlet EF port, the oil inlet P port of the priority valve (6) is connected with the steering pump (2), and the oil outlet CF port is connected with an oil inlet of the steering gear (3);
the reversing valve (7) comprises an oil inlet P port, an oil outlet PS port and an oil outlet PW port, the oil inlet P port of the reversing valve (7) is communicated with the oil outlet EF port of the priority valve (6), the oil outlet PS port is communicated with the oil tank (1), and the oil outlet PW port is communicated with the oil outlet of the working pump (4);
the pilot valve group is connected with the reversing valve (7), and a working oil port of the pilot valve group is communicated with a pilot end of the multi-way valve group (5); a port P of the pilot valve group is communicated with the working pump (4), and a port T is communicated with the oil tank (1);
the first detection piece (9) is arranged between the pilot valve group and the reversing valve (7) and is used for detecting the output pressure of the pilot valve group;
the second detection piece (10) is used for detecting the rotating speed of an engine (100) of the loader, and the reversing valve (7) can receive control signals of the first detection piece (9) and the second detection piece (10) to reverse, so that an oil outlet EF port of the priority valve (6) and an oil outlet PW port of the reversing valve (7) are communicated.
2. The hydraulic system of the loader as claimed in claim 1 further comprising a solenoid valve (8), wherein an oil inlet port P of the solenoid valve (8) is connected with the multi-way valve group (5), a working oil port is communicated with a pilot end of the reversing valve (7) and an oil return port T is communicated with the oil tank (1); the first detection piece (9) is arranged between the pilot valve group and the electromagnetic valve (8), and the electromagnetic valve (8) can receive control signals of the first detection piece (9) and the second detection piece (10) to conduct to enable the reversing valve (7) to reverse.
3. The hydraulic system of the loader of claim 2, wherein the pilot valve group comprises a boom pilot handle (11), a rotating bucket pilot handle (12) and a side dump pilot handle (13) which are connected with the working pump (4) and the oil tank (1), the boom pilot handle (11) is connected with an a2 oil port and a b2 oil port of a pilot end of a boom multi-way valve of the multi-way valve group (5), the rotating bucket pilot handle (12) is connected with an a1 oil port and a b1 oil port of a pilot end of a rotating bucket multi-way valve of the multi-way valve group (5), the side dump pilot handle (13) is connected with an a3 oil port and a b3 oil port of a pilot end of a side dump multi-way valve of the multi-way valve group (5), and the a2 oil port, the b1 oil port and the b3 oil port are all communicated with a P port of the solenoid valve (8) through the shuttle valve group.
4. The hydraulic system of the loader as claimed in claim 3, wherein the shuttle valve group comprises a first shuttle valve (14) and a second shuttle valve (15), the a2 oil port and the b3 oil port are respectively connected with two oil inlets of the first shuttle valve (14), the oil outlet of the first shuttle valve (14) and the b1 oil port are respectively connected with two oil inlets of the second shuttle valve (15), the oil outlet of the second shuttle valve (15) is connected with the solenoid valve (8), and the first detection member (9) is disposed between the oil outlet of the second shuttle valve (15) and the P port of the solenoid valve (8).
5. The hydraulic system of a loader as claimed in claim 2 wherein a throttle orifice (16) is provided in the connection line between the working port of the solenoid valve (8) and the pilot end of the directional valve (7).
6. The loader hydraulic system according to claim 2 further comprising an oil return filter element (17), wherein the oil return filter element (17) is communicated with the oil tank (1), and the oil outlet PS of the reversing valve (7), the oil return T of the solenoid valve (8) and the oil return of the pilot valve set are communicated with the oil return filter element (17).
7. Hydraulic system of a loader as claimed in claim 1 wherein the first detection member (9) is a pressure switch.
8. Hydraulic system of a loader as claimed in claim 1 wherein the second detection member (10) is a rotational speed sensor.
9. A loader hydraulic system according to claim 1 where the reversing valve (7) is a pilot operated reversing valve.
10. A loader comprising a loader hydraulic system according to any one of claims 1-9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110119347.8A CN112796366A (en) | 2021-01-28 | 2021-01-28 | Loader hydraulic system and loader |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110119347.8A CN112796366A (en) | 2021-01-28 | 2021-01-28 | Loader hydraulic system and loader |
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| Publication Number | Publication Date |
|---|---|
| CN112796366A true CN112796366A (en) | 2021-05-14 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110119347.8A Pending CN112796366A (en) | 2021-01-28 | 2021-01-28 | Loader hydraulic system and loader |
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| Country | Link |
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| CN (1) | CN112796366A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114909351A (en) * | 2022-07-19 | 2022-08-16 | 徐工集团工程机械股份有限公司科技分公司 | Quantitative closed-center hydraulic system and working method and control method thereof |
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| JPH07331705A (en) * | 1994-06-03 | 1995-12-19 | Shin Caterpillar Mitsubishi Ltd | Oil hydraulic circuit for turning of construction machine |
| JP2006290236A (en) * | 2005-04-13 | 2006-10-26 | Hitachi Constr Mach Co Ltd | Hydraulic drive device |
| CN103882897A (en) * | 2012-12-20 | 2014-06-25 | 青岛鲁达工程机械制造有限公司 | Loader hydraulic system |
| CN205190386U (en) * | 2015-10-21 | 2016-04-27 | 徐工集团工程机械股份有限公司科技分公司 | Improve hydraulic control system of loader energy -conservation nature |
| CN214497668U (en) * | 2021-01-28 | 2021-10-26 | 山东临工工程机械有限公司 | Loader hydraulic system and loader |
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- 2021-01-28 CN CN202110119347.8A patent/CN112796366A/en active Pending
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| JPH07331705A (en) * | 1994-06-03 | 1995-12-19 | Shin Caterpillar Mitsubishi Ltd | Oil hydraulic circuit for turning of construction machine |
| JP2006290236A (en) * | 2005-04-13 | 2006-10-26 | Hitachi Constr Mach Co Ltd | Hydraulic drive device |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN114909351A (en) * | 2022-07-19 | 2022-08-16 | 徐工集团工程机械股份有限公司科技分公司 | Quantitative closed-center hydraulic system and working method and control method thereof |
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