CN107761804B - Multi-pressure-level hydraulic excavator power source system - Google Patents
Multi-pressure-level hydraulic excavator power source system Download PDFInfo
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- CN107761804B CN107761804B CN201710965407.1A CN201710965407A CN107761804B CN 107761804 B CN107761804 B CN 107761804B CN 201710965407 A CN201710965407 A CN 201710965407A CN 107761804 B CN107761804 B CN 107761804B
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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
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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
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- Civil Engineering (AREA)
- General Engineering & Computer Science (AREA)
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- Fluid Mechanics (AREA)
- Fluid-Pressure Circuits (AREA)
- Operation Control Of Excavators (AREA)
Abstract
A multi-pressure-level hydraulic excavator power source system comprises a hydraulic excavator power source and a hydraulic excavator execution system control loop thereof, wherein the hydraulic excavator power source is characterized in that an oil outlet of a quantitative hydraulic pump A is communicated with an oil inlet of a variable hydraulic pump A; an oil outlet of the quantitative hydraulic pump B is communicated with an oil inlet of the variable hydraulic pump B; the prime motor provides prime power for the fixed-quantity hydraulic pump and the variable-quantity hydraulic pump; the hydraulic accumulator, the pressure sensor and the overflow valve are communicated with an oil outlet of the quantitative hydraulic pump; the one-way valves are positioned at two ends of the variable hydraulic pump; the oil inlet of the low-pressure loop control valve is communicated with the oil outlet of the quantitative hydraulic pump; an oil outlet of the low-pressure loop control valve is communicated with a low-pressure loop of the hydraulic excavator; the system realizes the control of at least four levels of the hydraulic system by the graded regulation and control of the fixed displacement pump and the variable displacement pump, and has the advantages of improving the rotating speed and the pressure of the hydraulic pump and further improving the working efficiency of the hydraulic pump.
Description
Technical Field
The invention belongs to the technical field of hydraulic power systems, and particularly relates to a power source system of a hydraulic excavator, which can be applied to positive flow or negative flow and multi-pressure-level output.
Background
In engineering applications, a hydraulic pump is a hydraulic component for powering a hydraulic system, and functions to convert mechanical energy of a prime mover into pressure energy of a fluid, a variable pump in which an output flow rate is adjusted as needed, a fixed displacement pump in which a flow rate is not adjusted, a high-speed hydraulic pump, a high-pressure hydraulic pump, a high-efficiency hydraulic pump, and a hydraulic pump having good load adaptability.
At present, the rated pressure of a large-flow variable plunger pump reaches 45MPa or even higher, and the total efficiency reaches more than 85 percent in most working ranges. In order to further increase the power density of hydraulic pumps, the trend of hydraulic pumps is to be able to withstand higher pressures and higher rotational speeds. However, further increasing the pressure level is limited by the pump structure, the strength of the parts and the bearing capacity of the key friction pair, and there are difficulties that are difficult to overcome in the technology. The increase of the rotation speed of the hydraulic pump is limited by the cavitation pressure of the pumping port of the pump under the normal oil supply pressure, and the technical improvement is limited only from the structural improvement. The technical difficulty and cost are high for further improving the pressure, the rotating speed and the efficiency of the pump.
Disclosure of Invention
The invention aims to provide a multi-pressure-level hydraulic excavator power source system which can work efficiently under low load pressure or high speed and high pressure.
Therefore, the invention provides a corresponding improvement way, a variable pump is replaced by a constant delivery pump with a variable rotating speed, the mode of outputting high pressure by a single pump is changed into the mode of utilizing double pumps to control the pressure of the pump in a grading way, the high speed and high pressure grade of the pump can be realized without changing the structure of the existing pump, the requirements of high and low pressure loads can be met simultaneously, and the functions of small volume and large flow of the hydraulic pump are realized.
In order to achieve the purpose, the technical scheme of the invention is that the hydraulic excavator power source system with multiple pressure levels comprises a hydraulic excavator power source and a hydraulic excavator execution system control loop thereof, wherein the hydraulic excavator power source comprises a quantitative hydraulic pump A, a quantitative hydraulic pump B, a variable hydraulic pump A, a variable hydraulic pump B, a prime motor A, a prime motor B, a one-way valve, a hydraulic energy accumulator, a pressure sensor, a low-pressure loop control valve and an overflow valve; the method is characterized in that:
the oil outlet of the quantitative hydraulic pump A is communicated with the oil inlet of the variable hydraulic pump A; an oil outlet of the quantitative hydraulic pump B is communicated with an oil inlet of the variable hydraulic pump B; an oil outlet of the variable hydraulic pump A is communicated with an oil inlet at the left end of a control loop of an execution system of the hydraulic excavator; an oil outlet of the variable hydraulic pump B is communicated with an oil inlet at the right end of a control loop of an execution system of the hydraulic excavator; the prime motor A provides prime power for the quantitative hydraulic pump A and the quantitative hydraulic pump B; the prime motor B provides prime power for the variable hydraulic pump A and the variable hydraulic pump A; the hydraulic accumulator, the pressure sensor and the overflow valve are communicated with an oil outlet of the quantitative hydraulic pump; the one-way valves are positioned at two ends of the variable hydraulic pump; the oil inlet of the low-pressure loop control valve is communicated with the oil outlet of the quantitative hydraulic pump; the oil outlet of the low-pressure loop control valve is communicated with a low-pressure loop of the hydraulic excavator;
the power source is provided with two modes of working by a single hydraulic pump or working by two hydraulic pumps simultaneously, when the load pressure is lower and the rotating speed of the hydraulic pumps is required to be low, the quantitative hydraulic pump A and the quantitative hydraulic pump B are adopted to independently work, and the output pressure of the quantitative hydraulic pump A and the output pressure of the quantitative hydraulic pump B are directly supplied to the control loop of the excavator execution system through the one-way valve; when the load pressure is high and the rotating speed of the hydraulic pump is required to be high, the quantitative hydraulic pump A is communicated with the variable hydraulic pump A, the quantitative hydraulic pump B is communicated with the variable hydraulic pump B, the four hydraulic pumps work simultaneously, redundant energy generated by the system is stored in the hydraulic accumulator, and the storage or release of the energy is determined through the pressure sensor; no matter the loop is a high-pressure load or a low-pressure load, the redundant pressure output by the quantitative hydraulic pump is output to the low-pressure loop for utilization through a low-pressure loop control valve; the overflow valve is a circuit protection.
The further technical characteristics are that: the power source in the hydraulic excavator system can realize the output of a plurality of pressure levels, and the system can realize the output of at least four different pressure levels by controlling the output pressure of four hydraulic pumps; the control loop of the hydraulic excavator execution system can be a negative flow control loop, a positive flow control loop or an inlet-outlet independent control loop, when the control loop is used for the negative flow control loop, a negative flow variable pump is adopted, and when the control loop is used for the positive flow control loop, a positive flow variable pump is adopted; the hydraulic pumps can be controlled and driven by the same prime mover at the same time or by respective prime movers; the prime mover is one of an electric motor, an internal combustion engine, and a flywheel-less engine.
Compared with the prior art, the multi-pressure-level hydraulic excavator power source system provided by the invention has the following characteristics:
firstly, the high-speed and high-pressure grade of the pump can be realized on the basis of not changing the structure of the existing pump, the requirements of high and low pressure loads can be met simultaneously, and the functions of small volume and large flow of the hydraulic pump can be realized.
Secondly, the constant delivery pump can work independently and be applied to a low-pressure loop, and can work simultaneously with the variable delivery pump and be applied to a high-pressure loop, thereby reducing the throttling loss of a valve port and improving the output pressure and the output rotating speed of the pump.
Thirdly, the excess pressure output by the constant delivery pump can be supplied to the low-pressure loop to meet the load requirement.
And fourthly, an energy accumulator is arranged in a power source loop, redundant energy output by the hydraulic pump can be stored and recycled, the system heating is reduced, the continuous working time of the machine is prolonged, and the problem that the oil tank is easy to age due to high temperature for a long time is solved.
Drawings
FIG. 1 is a schematic diagram of a multi-pressure-level hydraulic excavator power source system of the present invention.
Fig. 2 is a schematic diagram of the system architecture of the present invention in which a single prime mover controls four hydraulic pumps.
Fig. 3 is a schematic diagram of a system for controlling a fixed displacement pump and a variable displacement pump simultaneously by a single prime mover according to the present invention.
In the figure: 1: quantitative hydraulic pumps a, 2: quantitative hydraulic pumps B, 3: variable hydraulic pumps a, 4: variable hydraulic pumps B, 5: prime mover a, 6: prime mover B, 7: one-way valve, 8: hydraulic accumulator, 9: pressure sensor, 10: low-pressure circuit control valve, 11: relief valve, 12: travel motor control valve, 13: travel motor, 14: bucket control valve, 15: bucket cylinder, 16: boom control valve, 17: boom cylinder, 18: arm control valve, 19: bucket rod hydraulic cylinder, 20: rotation motor control valve, 21: a rotary motor.
Detailed description of the preferred embodiments
The following further describes embodiments of the present invention with reference to the accompanying drawings.
Example 1
As shown in fig. 1, a hydraulic excavator power source system with multiple pressure levels comprises a hydraulic excavator power source and a hydraulic excavator execution system control circuit, wherein the hydraulic excavator execution system control circuit comprises a walking motor control valve 12, a walking motor 13, a bucket control valve 14, a bucket hydraulic cylinder 15, a boom control valve 16, a boom hydraulic cylinder 17, an arm control valve 18, an arm hydraulic cylinder 19, a swing motor control valve 20 and a swing motor 21, and is characterized in that: the hydraulic excavator power source comprises a quantitative hydraulic pump A1, a quantitative hydraulic pump B2, a variable hydraulic pump A3, a variable hydraulic pump B4, a prime mover A5, a prime mover B6, a one-way valve 7, a hydraulic accumulator 8, a pressure sensor 9, a low-pressure loop control valve 10 and an overflow valve 11, wherein an oil outlet of the quantitative hydraulic pump A1 is communicated with an oil inlet of the variable hydraulic pump A3; an oil outlet of the quantitative hydraulic pump B2 is communicated with an oil inlet of the variable hydraulic pump B4; an oil outlet of the variable hydraulic pump A3 is communicated with an oil inlet at the left end of a control loop of an execution system of the hydraulic excavator; an oil outlet of the variable hydraulic pump B4 is communicated with an oil inlet at the right end of a control loop of an execution system of the hydraulic excavator; the prime mover A5 provides prime power for the fixed displacement hydraulic pump A1 and the fixed displacement hydraulic pump B2; the prime mover B6 provides prime power to the variable hydraulic pump A3 and the variable hydraulic pump A4; the hydraulic accumulator 8, the pressure sensor 9 and the overflow valve 11 are communicated with an oil outlet of the quantitative hydraulic pump; the check valves 7 are positioned at two ends of the variable hydraulic pump; the oil inlet of the low-pressure loop control valve 10 is communicated with the oil outlet of the quantitative hydraulic pump; the oil outlet of the low-pressure loop control valve 10 is communicated with a low-pressure loop of the hydraulic excavator.
When the load of the circuit is low pressure, the quantitative hydraulic pump A1 and the quantitative hydraulic pump B2 output the same or different pressure through the driving of the prime mover 5 according to the actual load requirement, so as to realize the output of two levels; oil outlets of the quantitative hydraulic pump A1 and the quantitative hydraulic pump B2 are communicated with the check valve 7, output pressure can be directly supplied to a control loop of an excavator execution system, and redundant pressure output by the quantitative hydraulic pump A1 and the quantitative hydraulic pump B2 can be output to a low-pressure loop through the low-pressure loop control valve 10 and used for driving low-pressure execution elements in the excavator hydraulic system, so that the energy utilization rate is improved; when the load of the circuit is high pressure, the quantitative hydraulic pump A1 and the quantitative hydraulic pump B2 are required to work simultaneously with the variable hydraulic pump A3 and the variable hydraulic pump B4, the variable hydraulic pump A3 and the variable hydraulic pump B4 are driven by the prime mover 6 to output the same or different pressures, so that the output of four pressure levels is realized, and the output pressure is supplied to an excavator execution system control circuit through oil outlets of the variable hydraulic pump A3 and the variable hydraulic pump B4; the excess energy generated in the circuit is stored in the hydraulic accumulator 8, the storage or release of energy being determined by the pressure sensor 9; the overflow valve 11 mainly plays a role of loop protection.
In the above embodiment, the power source in the excavator hydraulic system can realize output of multiple pressure levels, and the system can realize output of four different pressure levels by controlling the output pressure of the four hydraulic pumps.
In the above-described embodiment, the hydraulic excavator implement system control circuit is a negative flow control circuit, and the variable displacement hydraulic pump used in the power source is a negative flow variable displacement pump.
In the above embodiment, the fixed displacement hydraulic pumps are driven by the same prime mover while the variable displacement hydraulic pumps are driven by the other prime mover while being controlled.
In the above embodiments, the prime mover is an internal combustion engine.
Example 2
As shown in fig. 2, the connection mode and the operation principle of each hydraulic component of the excavator system are similar to those of embodiment 1, and the difference is that the motor 5 in the power source drives four hydraulic pumps, namely, a fixed-quantity hydraulic pump a1, a fixed-quantity hydraulic pump B2, a variable-quantity hydraulic pump A3 and a variable-quantity hydraulic pump B4, respectively, and the four hydraulic pumps can determine the pressure of an output oil path respectively according to the requirement of actual load, so that the output of four pressure levels can be realized, and the installation space of the hydraulic system can be reduced.
In the above embodiment, the power source in the excavator hydraulic system can realize output of multiple pressure levels, and the system can realize output of four different pressure levels by controlling the output pressure of the four hydraulic pumps.
In the above-described embodiment, the hydraulic excavator implement system control circuit is a positive flow rate control circuit, and the variable displacement hydraulic pump used in the power source is a positive flow rate variable pump.
In the above embodiment, both the fixed displacement hydraulic pump and the variable displacement hydraulic pump are driven by the same prime mover by simultaneous control. In the above embodiments, the prime mover is an internal combustion engine.
Example 3
As shown in fig. 3, the connection mode and the operation principle of each hydraulic component of the excavator system are similar to those of embodiment 1, except that the prime mover 5 in the left half of the power source drives the fixed-quantity hydraulic pump a1 and the variable-quantity hydraulic pump A3, and the prime mover 6 in the right half of the power source drives the fixed-quantity hydraulic pump B2 and the variable-quantity hydraulic pump B4, and the output of four pressure levels can be realized according to the requirement of the actual load.
In the above embodiment, the power source in the excavator hydraulic system can realize output of multiple pressure levels, and the system can realize output of four different pressure levels by controlling the output pressure of the four hydraulic pumps.
In the above-described embodiment, the hydraulic excavator implement system control circuit is a negative flow control circuit, and the variable displacement hydraulic pump used in the power source is a negative flow variable displacement pump.
In the above embodiment, the fixed-displacement hydraulic pump a1 and the variable-displacement hydraulic pump A3 on the left side are driven by the same prime mover, and the fixed-displacement hydraulic pump B1 and the variable-displacement hydraulic pump B3 on the right side are driven by the same prime mover.
In the above embodiments, the prime mover is an electric motor.
Claims (4)
1. A multi-pressure-level hydraulic excavator power source system comprises a hydraulic excavator power source and a hydraulic excavator execution system control loop, wherein the hydraulic excavator power source comprises a quantitative hydraulic pump A (1), a quantitative hydraulic pump B (2), a variable hydraulic pump A (3), a variable hydraulic pump B (4), a prime mover A (5), a prime mover B (6), a check valve (7), a hydraulic energy accumulator (8), a pressure sensor (9), a low-pressure loop control valve (10) and an overflow valve (11); the method is characterized in that:
an oil outlet of the quantitative hydraulic pump A (1) is communicated with an oil inlet of the variable hydraulic pump A (3); an oil outlet of the quantitative hydraulic pump B (2) is communicated with an oil inlet of the variable hydraulic pump B (4); an oil outlet of the variable hydraulic pump A (3) is communicated with an oil inlet at the left end of a control loop of an execution system of the hydraulic excavator; an oil outlet of the variable hydraulic pump B (4) is communicated with an oil inlet at the right end of a control loop of an execution system of the hydraulic excavator; the prime motor A (5) provides prime power for the quantitative hydraulic pump A (1) and the quantitative hydraulic pump B (2); the prime motor B (6) provides prime power for the variable hydraulic pump A (3) and the variable hydraulic pump B (4); the hydraulic accumulator (8), the pressure sensor (9) and the overflow valve (11) are communicated with an oil outlet of the quantitative hydraulic pump; the check valves (7) are positioned at two ends of the variable hydraulic pump; an oil inlet of the low-pressure loop control valve (10) is communicated with an oil outlet of the quantitative hydraulic pump; an oil outlet of the low-pressure loop control valve (10) is communicated with a hydraulic excavator execution system control loop; when the load pressure is low and the rotating speed of the hydraulic pump is required to be low, the power source adopts the quantitative hydraulic pump A (1) and the quantitative hydraulic pump B (2) to independently work, and directly supplies the output pressure of the quantitative hydraulic pump A (1) and the output pressure of the quantitative hydraulic pump B (2) to an excavator execution system control loop through the one-way valve (7); when the load pressure is high and the rotating speed of the hydraulic pump is required to be high, the quantitative hydraulic pump A (1) is communicated with the variable hydraulic pump A (3), the quantitative hydraulic pump B (2) is communicated with the variable hydraulic pump B (4), the four hydraulic pumps work simultaneously, redundant energy generated by the system is stored in the hydraulic energy accumulator (8), and the storage or release of the energy is determined through the pressure sensor (9); no matter the high-pressure load or the low-pressure load of the loop, the excess pressure output by the quantitative hydraulic pump is output to the low-pressure loop through a low-pressure loop control valve (10), so that the energy utilization rate is improved; the overflow valve (11) is used for loop protection; the power source in the hydraulic system of the hydraulic excavator comprises at least four outputs with different pressure levels, and the output pressure of the four hydraulic pumps is controlled.
2. The multi-pressure-level hydraulic excavator power source system of claim 1, wherein: the control loop of the hydraulic excavator execution system is a negative flow control loop, a positive flow control loop or an inlet and outlet independent control loop, when the control loop is used for the negative flow control loop, a negative flow variable pump is adopted, and when the control loop is used for the positive flow control loop, a positive flow variable pump is adopted.
3. The multi-pressure-level hydraulic excavator power source system of claim 1, wherein: the hydraulic pumps are driven by the same prime mover at the same time or by separate prime movers.
4. The multi-pressure-level hydraulic excavator power source system of claim 1, wherein: the prime mover is one of an electric motor, an internal combustion engine, and a flywheel-less engine.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201710965407.1A CN107761804B (en) | 2017-10-17 | 2017-10-17 | Multi-pressure-level hydraulic excavator power source system |
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| CN201710965407.1A CN107761804B (en) | 2017-10-17 | 2017-10-17 | Multi-pressure-level hydraulic excavator power source system |
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| CN107761804B true CN107761804B (en) | 2020-03-27 |
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| CN108644091B (en) * | 2018-06-19 | 2019-09-03 | 姚长水 | A kind of device and its flow rate adjusting method of adjustable quantitative hydraulic pump flow |
| CN109058195B (en) * | 2018-10-30 | 2024-04-30 | 江苏徐工工程机械研究院有限公司 | Hydraulic control system of rescue equipment and rescue equipment |
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| JP3528981B2 (en) * | 1994-08-30 | 2004-05-24 | 株式会社小松製作所 | Hydraulic circuit for boom cylinder of hydraulic excavator |
| JP4624203B2 (en) * | 2005-07-22 | 2011-02-02 | カヤバ工業株式会社 | Hydraulic control device for construction machinery |
| CN2906133Y (en) * | 2006-04-11 | 2007-05-30 | 程江伟 | Variable displacement pump |
| CN204703220U (en) * | 2015-06-12 | 2015-10-14 | 圣邦集团有限公司 | Loading machine quantitative pump and variable pump multiplex control system |
| CN105839689B (en) * | 2016-04-26 | 2018-01-16 | 华侨大学 | The more motor hydraulic excavating mechanical electronic hydraulic hybrid drive systems of multiple-energy-source and control method |
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