US20220065272A1 - Hydraulic variable pump set and excavator - Google Patents
Hydraulic variable pump set and excavator Download PDFInfo
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- US20220065272A1 US20220065272A1 US17/418,421 US201817418421A US2022065272A1 US 20220065272 A1 US20220065272 A1 US 20220065272A1 US 201817418421 A US201817418421 A US 201817418421A US 2022065272 A1 US2022065272 A1 US 2022065272A1
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- component
- oil
- control valve
- valve
- pump
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B13/00—Details of servomotor systems ; Valves for servomotor systems
- F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
- F15B13/06—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with two or more servomotors
-
- 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
- E02F9/226—Safety arrangements, e.g. hydraulic driven fans, preventing cavitation, leakage, overheating
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
- F15B15/20—Other details, e.g. assembly with regulating devices
- F15B15/204—Control means for piston speed or actuating force without external control, e.g. control valve inside the piston
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
- B60K15/00—Arrangement in connection with fuel supply of combustion engines or other fuel consuming energy converters, e.g. fuel cells; Mounting or construction of fuel tanks
- B60K15/03—Fuel tanks
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F3/00—Dredgers; Soil-shifting machines
- E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
-
- 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
- E02F9/2296—Systems with a variable displacement pump
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
- F04B1/12—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis
- F04B1/26—Control
- F04B1/30—Control of machines or pumps with rotary cylinder blocks
- F04B1/32—Control of machines or pumps with rotary cylinder blocks by varying the relative positions of a swash plate and a cylinder block
- F04B1/324—Control of machines or pumps with rotary cylinder blocks by varying the relative positions of a swash plate and a cylinder block by changing the inclination of the swash plate
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
- B60K15/00—Arrangement in connection with fuel supply of combustion engines or other fuel consuming energy converters, e.g. fuel cells; Mounting or construction of fuel tanks
- B60K15/03—Fuel tanks
- B60K2015/03243—Fuel tanks characterised by special pumps, the mounting thereof
-
- 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
- E02F9/08—Superstructures; Supports for superstructures
- E02F9/0858—Arrangement of component parts installed on superstructures not otherwise provided for, e.g. electric components, fenders, air-conditioning units
- E02F9/0883—Tanks, e.g. oil tank, urea tank, fuel tank
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/22—Hydraulic or pneumatic drives
- E02F9/2221—Control of flow rate; Load sensing arrangements
- E02F9/2225—Control of flow rate; Load sensing arrangements using pressure-compensating valves
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/22—Hydraulic or pneumatic drives
- E02F9/2221—Control of flow rate; Load sensing arrangements
- E02F9/2232—Control of flow rate; Load sensing arrangements using one or more variable displacement pumps
- E02F9/2235—Control of flow rate; Load sensing arrangements using one or more variable displacement pumps including an electronic controller
-
- 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
- E02F9/2285—Pilot-operated systems
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
- F15B2211/205—Systems with pumps
- F15B2211/2053—Type of pump
- F15B2211/20546—Type of pump variable capacity
- F15B2211/20553—Type of pump variable capacity with pilot circuit, e.g. for controlling a swash plate
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
- F15B2211/205—Systems with pumps
- F15B2211/20576—Systems with pumps with multiple pumps
Definitions
- the present disclosure relates to the technical field of hydraulic pumps, for example, to a hydraulic variable pump set and an excavator.
- Patent CN105113570A discloses a hydraulic component configuration of an excavator.
- the hydraulic oil provided by a main pump enters a negative flux feedback valve after passing through a main control valve, and a pressure signal is generated through an orifice of the negative flux feedback valve.
- the pressure signal controls a displacement adjustment mechanism of the main pump to adjust a flux of the main pump.
- Patent CN104480991A discloses a hydraulic pump control circuit of an excavator.
- a first variable pump controls the change in the relationship between outlet pressure and displacement through a first variable pump adjustment mechanism
- a second variable pump controls the change in the relationship between outlet pressure and displacement through a second variable pump adjustment mechanism.
- Each of the first variable pump adjustment mechanism and the second variable pump adjustment mechanism includes four control signals, where a power curve of a variable pump is controlled by three signals, that is, first variable pump outlet pressure, second variable pump outlet pressure, and a power control signal; and displacement of the variable pump is controlled by a fourth control signal.
- the positions of a movable arm cylinder, a stick cylinder, and a bucket cylinder are determined by a movable arm cylinder displacement sensor, a stick cylinder displacement sensor, a bucket cylinder displacement sensor, the first variable pump outlet pressure, and the second variable pump outlet pressure; based on the above, the first variable pump and the second variable pump are controlled.
- the displacement of the variable pump is controlled through a feedback signal of an external control system.
- the control system is complicated in structure and high in cost, the follow-up maintenance is complicated, and the system is large in volume and takes up a large space.
- the present disclosure provides a hydraulic variable pump set and an excavator.
- a structure configured to control output displacement of a variable pump can be integrated with the variable pump, and multiple control components can be integrated so that different control functions can be achieved, and advantages such as a simple structure and a small volume can be achieved.
- An embodiment provides a hydraulic variable pump set.
- the hydraulic variable pump set includes a pump body component and an oil supplement component.
- the pump body component includes a pump body, a first slide valve, and a first control valve.
- the first slide valve includes a spring end and a pilot cavity, and the first control valve is provided with an oil inlet A, an oil inlet B, and an oil outlet T.
- the pump body includes a variable pump and a variable cylinder.
- the variable pump includes a swash plate, the variable cylinder includes a rod cavity and a rodless cavity, the variable cylinder is mechanically connected to the spring end and the swash plate, and the oil supplement component is in communication with the pilot cavity.
- variable pump is in communication with the oil inlet A of the first control valve
- the oil supplement component is in communication with the oil inlet B of the first control valve
- the oil outlet T of the first control valve is in communication with the rod cavity
- the rodless cavity is in communication with the oil outlet T of the first control valve through the first slide valve.
- An embodiment further provides an excavator, and the excavator includes the hydraulic variable pump set.
- FIG. 1 is a structure diagram of a working principle of a hydraulic variable pump set according to an embodiment of the present disclosure.
- FIG. 2 is a structure diagram of the hydraulic variable pump set according to an embodiment of the present disclosure.
- the hydraulic variable pump set includes a pump body component 1 , an oil supplement component 2 , an electronically-controlled pressure relief component 4 , a failure-safety component 5 , and a pressure cutoff component 6 .
- the pump body component 1 includes a pump body 11 , a first slide valve 12 , and a first control valve 13 .
- the pump body 11 includes a variable pump 111 and a variable cylinder 112 .
- the variable pump 111 is a one-way variable pump
- an oil inlet of the variable pump 111 is in communication with a fuel tank 3
- an oil outlet of the variable pump 111 is connected to an oil inlet A of the first control valve 13
- the oil supplement component 2 is in communication with an oil inlet B of the first control valve 13
- an oil outlet T of the first control valve 13 is in communication with a rod cavity 1122 of the variable cylinder 112 through one pipeline
- a rodless cavity 1123 of the variable cylinder 112 is in communication with the oil outlet T and the fuel tank 3 through the first slide valve 12 .
- Hydraulic oil provided by the oil supplement component 2 for the first control valve 13 is used as control pilot oil of the first control valve 13
- the variable pump 111 also provides oil for the first control valve 13 .
- the first control valve 13 is used as a selection valve, and one of the hydraulic oil provided by the oil supplement component 2 or the hydraulic oil provided by the variable pump 111 whose pressure is relatively high is selected as a control oil source of the first control valve 13 .
- the first control valve 13 is a shuttle valve and may also be a two-position two-way solenoid valve.
- the variable cylinder 112 is mechanically connected to a pilot cavity 122 of the first slide valve 12 and a swash plate 111 of the variable pump 111 .
- a piston rod 1121 of the variable cylinder 112 is mechanically connected to the swash plate 111 of the variable pump 111
- the swash plate 111 of the variable pump 111 is connected to a feedback rod 14
- the feedback rod 14 is connected to the pilot cavity 122 of the first slide valve 12 .
- the movement of the variable cylinder 112 acts on the pilot cavity 121 through the feedback rod 14 .
- the pilot cavity 121 of the first slide valve 12 is in communication with the oil supplement component 2 .
- the oil supplement component 2 provides pilot oil for the first slide valve 12 .
- the pilot oil provided by the oil supplement component 2 pushes a valve element of the first slide valve 12 to move.
- the oil outlet of the variable pump 111 is in communication with an external hydraulic control system through a port P 1 in FIG. 1 so that various movements of an excavator can be controlled.
- the valve element of the first slide valve 12 is at a preset position, that is, the pressure applied by the pilot oil on one side of the valve element of the first slide valve 12 is the same as the pressure applied by a spring on the other side of the valve element of the first slide valve 12 .
- the pressure of the rod cavity 1122 of the variable cylinder 112 is balanced with the pressure of the rodless cavity 1123 of the variable cylinder 112 .
- the spring of the first slide valve 12 is compressed, and the valve element of the first slide valve 12 is at a leftmost position. In this case, the movement of the feedback rod 14 toward the left always changes the compression amount of the spring, and the spring is not in a stretched state.
- the oil supplement component 2 is controlled to provide the pilot oil for the pilot cavity 121 at a right end of the first slide valve 12 , and the pressure in the pilot cavity 121 increases.
- the valve element of the first slide valve 12 moves toward the left. If the pressure of the hydraulic oil output from the oil outlet of the variable pump 111 is greater than the pressure of the hydraulic oil provided by the oil supplement component 2 , a valve element of the first control valve 13 moves upward, and the path on which the hydraulic oil provided by the variable pump 111 passes through the first control valve 13 is from the oil inlet A to the oil outlet T.
- the oil outlet T of the first control valve 13 is branched to the rod cavity 1122 and the rodless cavity 1123 of the variable cylinder 112 through pipelines, that is, the oil outlet T of the first control valve 13 is directly in communication with the rod cavity 1122 of the variable cylinder 112 through a first branch, and the oil outlet T of the first control valve 13 is in communication with the rodless cavity 1123 of the variable cylinder 112 through an internal passage of the first slide valve 12 on a second branch.
- the movement of the valve element of the first slide valve 12 affects the opening degree of a valve port.
- the opening degree of an oil port on the first slide valve 12 along a direction in which the hydraulic oil enters the rodless cavity 1123 becomes smaller
- the opening degree of an oil port on the rodless cavity 1123 along a direction in which the hydraulic oil flows from the first slide valve 12 to the fuel tank 3 becomes larger
- the pressure in the rodless cavity 1123 becomes lower.
- a force applied by the hydraulic oil in the rod cavity 1122 of the variable cylinder 112 on a piston is greater than a force applied by the hydraulic oil in the rodless cavity 1123 on the piston, and the piston A is pushed to move toward the right.
- the swash plate 111 is pushed through the piston rod 1121 .
- a swing angle of the swash plate 111 can be increased, the displacement of the variable pump 111 can be increased, the swash plate 111 drives the feedback rod 14 , and the feedback rod 14 acts on the pilot cavity 122 so that the valve element of the first slide valve 12 moves toward the right.
- the rodless cavity 1123 and the rod cavity 1122 reach a balanced state, and the valve element of the first slide valve 12 is stabilized at a preset position again.
- the displacement of the variable pump 111 has a stable output.
- One of a pilot oil source provided by the oil supplement component 2 or the hydraulic oil provided by the variable pump 111 whose pressure is relatively high is used as the control oil source of the first control valve 13 .
- an outlet P 1 of the variable pump 111 is connected to an external load. Therefore, in the case where the variable pump 111 is working, the pressure generated in a pipeline between the variable pump 111 and the first control valve 13 is greater than the pressure of the pilot oil provided by the oil supplement component 2 , and the hydraulic oil provided by the variable pump 111 is used as control oil of the first control valve 13 .
- variable pump 111 when the variable pump 111 is working, if the pipeline between the variable pump 111 and the first control valve 13 cannot generate oil pressure capable of pushing the valve element of the first control valve 13 to move, oil cannot enter the oil inlet A (for example, when the equipment is always in a slipping state, since the pressure in the hydraulic variable pump set is determined by the load, in this case, if the pressure cannot be established between the variable pump 111 and the first control valve 13 ); and if the output displacement of the variable pump 111 needs to be adjusted, since pressure cannot be established in the pipeline between the variable pump 111 and the first control valve 13 , hydraulic oil output from the variable pump 111 cannot flow to the variable cylinder 112 through the first control valve 13 , the hydraulic oil in the rodless cavity 1123 and the rod cavity 1122 in the variable cylinder 112 basically does not change, and the variable displacement of the variable pump 111 cannot be achieved.
- the oil supplement component 2 is used as the control oil source of the first control valve 13 , hydraulic oil in the oil supplement component 2 is divided into the first branch and the second branch after passing through the oil inlet B and the oil outlet T of the first control valve 13 , the hydraulic oil is provided for the rodless cavity 1123 of the variable cylinder 112 through the first branch, and the hydraulic oil is provided for the rod cavity 1122 through the second branch; after the hydraulic oil is provided for the variable cylinder 112 , the piston rod 1121 starts to move; and finally the piston rod 1121 of the variable cylinder 112 reaches a balanced state again.
- the swash plate 111 of the variable pump 111 moves with the piston rod 1121 , and the feedback rod 14 is driven by the swash plate 111 to move.
- the valve element of the first slide valve 12 is in a stable state, the displacement of the variable pump 111 remained stable again.
- An oil inlet 42 of the electronically-controlled pressure relief component 4 is in communication with the oil supplement component 2
- an oil outlet 43 of the electronically-controlled pressure relief component 4 is in communication with the pump body component 1
- the electronically-controlled pressure relief component 4 may control the pressure of the pilot oil source provided by the oil supplement component 2 for the pump body component 1 .
- the electronically-controlled pressure relief component 4 includes a solenoid valve 41 , and the pressure of the hydraulic oil output to the pump body component 1 is controlled by the solenoid valve 41 .
- the solenoid valve 41 is an electronically-controlled proportional pressure relief valve. An output end of the solenoid valve 41 is connected to the pilot cavity 121 of the first slide valve 12 . When the control system sends out a current signal, the solenoid valve 41 starts to work, and input pressure of the solenoid valve 41 comes from the oil supplement component 2 .
- One side of the solenoid valve 41 is provided with a control terminal, and an input current signal enables the control terminal to push the valve element inside the solenoid valve 41 to move so that the opening degree of an oil circuit in the solenoid valve 41 can be adjusted, and thus the pressure of the hydraulic oil at the outlet of the solenoid valve 41 can be adjusted.
- outlet pressure of the solenoid valve 41 is proportional to the input current signal, that is, the pressure of the hydraulic oil at the outlet of the solenoid valve 41 increases as the current increases, showing a linear proportional relationship.
- a failure-safety component 5 is disposed in a pipeline between the electronically-controlled pressure relief component 4 and the pump body component 1 , the failure-safety component 5 is a pilot control valve, and the working state of the failure-safety component 5 is controlled by the electronically-controlled pressure relief component 4 .
- the oil supplement component 2 provides oil for the pilot cavity 121 of the first slide valve 12 through the electronically-controlled pressure relief component 4 and the failure-safety component 5 .
- the oil supplement component 2 provides oil for the pilot cavity 121 of the first slide valve 12 through the failure-safety component 5 .
- the failure-safety component 5 includes a second control valve 51 .
- the output end of the solenoid valve 41 is in communication with an oil port A of the second control valve 51 and is in communication with a pilot cavity of the second control valve 51
- the oil supplement component 2 is in communication with an oil port B of the second control valve 51 .
- the oil supplement component 2 provides oil for the pilot cavity 121 of the first slide valve 12 through the failure-safety component 5 .
- no pilot oil exists in the pilot cavity of the second control valve 51
- the second control valve 51 is in a right working state
- the oil port B of the second control valve 51 is always in communication with the pilot cavity 121 of the first slide valve 12 .
- the oil is divided into two paths after entering the second control valve 51 from the oil port B, where one path is in communication with the pilot cavity 121 of the first slide valve 12 , and the other path is in communication with the fuel tank; in addition, the path in communication with the fuel tank is provided with an orifice.
- part of the hydraulic oil from an outlet of the electronically-controlled pressure relief component 4 is used as pilot oil and acts on one end of the second control valve 51 so that the second control valve 51 is in a left working state.
- the oil port B is closed, and the oil in the oil supplement component 2 may only communicate with the second control valve 51 through the electronically-controlled pressure relief component 4 and then communicate with the pilot cavity 121 of the first slide valve 12 .
- the pilot cavity 121 of the first slide valve 12 is in communication with the oil supplement component 2 , and the control pressure of the pilot cavity 121 of the first slide valve 12 is adjusted by different working positions of the electronically-controlled pressure relief component 4 and the failure-safety component 5 .
- the second control valve 51 is a two-position four-way servo slide valve, and oil can pass through the second control valve 51 in two directions.
- a pressure cutoff component 6 is provided.
- the pressure cutoff component 6 is connected to a pipeline between the first control valve 13 and the first slide valve 12 . In the case where the output pressure of the variable pump 111 reaches a preset pressure threshold, the pressure cutoff component 6 operates so that the rod cavity 1122 of the variable cylinder 112 is in communication with the rodless cavity 1123 of the variable cylinder 112 .
- the pressure cutoff component 6 includes a third control valve 61 , where the third control valve 61 is a two-position three-way servo slide valve, the oil outlet T of the first control valve 13 may simultaneously communicate with a pilot end 611 of the third control valve 61 and an oil port A of the third control valve 61 , and an oil port T of the third control valve 61 is in communication with the first slide valve 12 .
- the rodless cavity 1123 of the variable cylinder 112 is always in communication with the fuel tank 3 through the first slide valve 12 and the third control valve 61 .
- the rodless cavity 1123 of the variable cylinder 112 is in communication with the fuel tank 3 through an internal passage of the second control valve 12 , the oil port T of the third control valve 61 , and the oil port B of the third control valve 61 .
- the rod cavity 1122 of the variable cylinder 112 may communicate with the rodless cavity 1123 of the variable pump 111 through the third control valve 61 and the first slide valve 12 .
- the rodless cavity 1123 is still in communication with the fuel tank 3 .
- the third control valve 61 is at the right working state.
- the rod cavity 1122 of the variable cylinder 112 does not communicate with the rodless cavity 1123 of the variable cylinder 112 .
- the rodless cavity 1123 of the variable cylinder 112 is in communication with the fuel tank through the first slide valve 12 and the third control valve 61 .
- variable pump 111 is applied to an excavator, in the case where the displacement of the variable pump 111 is very large and the movement of the excavator is blocked, a port P 1 of the hydraulic variable pump set in this embodiment is connected to an external load system, the external load system controls the pressure in pipelines of the hydraulic variable pump set in this embodiment, and the pressure is determined by the external load system.
- the pressure cutoff component 6 takes effect, that is, the valve element of the third control valve 61 moves.
- the valve element of the third control valve 61 moves so that the rodless cavity 1123 is in communication with the rod cavity 1122 , and the displacement of the variable pump 111 can be controlled through the adjustment of the variable cylinder 112 .
- the displacement of the variable pump 111 is controlled so that the purpose of controlling the output power of the variable pump 111 can be achieved.
- hydraulic oil from the oil outlet T of the first control valve 13 is used as pilot oil of the third control valve 61 and acts on the pilot end 611 of the third control valve 61 , and the valve element of the third control valve 61 is pushed to move toward the right. In this case, the rodless cavity 1123 is in communication with the rod cavity 1122 .
- the rod cavity 1122 and the rodless cavity 1123 are high-pressure oil, and the hydraulic oil returning to the fuel tank causes less pressure drop in the rodless cavity 1123 .
- the pressure applied by the hydraulic oil in the rodless cavity 1123 on the piston is gradually greater than the pressure applied by the hydraulic oil in the rod cavity 1122 on the piston, and the piston is pushed to move toward the left.
- the swing angle of the swash plate 111 becomes smaller, and the output displacement of the variable pump 111 becomes the small displacement until the two cavities are in the balanced state, and the output displacement of the variable pump 111 is stable again.
- the first slide valve 12 and the third control valve 61 are used as variable control valves of the variable pump 111 , the variable direction and variable degree of the variable pump 111 are controlled according to the pressure of the pilot oil, and the magnitudes of the openings of the first slide valve 12 and the third control valve 61 are in a linear proportional relationship with the variable degree of the variable pump 111 .
- the oil supplement component 2 includes an oil supplement pump 21 and an overflow valve 22 .
- An oil outlet 211 of the oil supplement pump 21 is connected to the pump body component 1 , the failure-safety component 5 , and the pressure cutoff component 6 .
- the oil supplement pump 21 provides pilot oil for the preceding multiple components.
- the oil supplement pump 21 is in communication with the solenoid valve 41 , the first control valve 13 , and the second control valve 51 through a filter 23 .
- the overflow valve 22 is in communication with and in parallel with the oil supplement pump 21 , and the oil supplement pump 21 is in a form of a quantitative gear pump and is integrated with the overflow valve.
- the output flux of the quantitative gear pump is constant, while the system controls the oil to continuously change according to the requirements. Therefore, based on a case where it is ensured that the pilot oil required by the multiple components of the system is provided, the rest of the hydraulic oil is overflowed to the fuel tank 3 through the overflow valve 22 , and part of the hydraulic oil is overflowed to an oil suction port of the oil supplement pump 21 so that the balance of system cooling and energy saving can be achieved.
- the hydraulic variable pump set includes two pump body components 1 , and each pump body component 1 corresponds to one electronically-controlled pressure relief component 4 , one failure-safety component 5 , and one pressure cutoff component 6 .
- each pump body component 1 is correspondingly connected to one solenoid valve 41 , one second control valve 51 , and one third control valve 61 .
- Variable pumps 111 of the two pump bodies 11 communicate with each other, but the variable pumps 111 of the two pump bodies 11 are controlled independently of each other.
- An output end of the variable pump 111 of one pump body 11 is provided with a port P 1
- an output end of the variable pump 111 of the other pump body 11 is provided with a port P 2
- each of the P 2 port and the P 1 port is configured to communicate with the external hydraulic control system so that various movements of the excavator can be achieved.
- variable pumps 111 of the two pump body components 1 and the oil supplement pump 21 of one oil supplement component 2 are connected in series and in sequence.
- Drive shafts of the two variable pumps 111 and a drive shaft of the oil supplement pump 21 are connected in series and in sequence, and the same engine (motor) is shared for driving so that a triple pump structure is formed.
- the two pump body components 1 , the two electronically-controlled pressure relief components 4 , the two failure-safety components 5 , and the two pressure cutoff components 6 all share one oil supplement component 2 , and the oil supplement component 2 provides pilot oil.
- the two electronically-controlled pressure relief components 4 can individually control different oil pressure outputs.
- multiple functions of the main hydraulic pump of the excavator can be achieved, and the multiple functions include an electronic proportional control function, a pressure cutoff function, a failure-safety function, and an oil supplement function.
- Power control can be achieved by combining with the electronic control component. Advantages such as sound functions, a reasonable structure, simple control, and high reliability can be achieved so that the use requirements of the excavator can be fully satisfied.
- the hydraulic pump in the case where the electrical control system of the excavator fails, the hydraulic pump can automatically reach the maximum displacement so that it is ensured that the excavator can perform work and walking functions.
- the component arrangement is adopted, and functional components can be added or removed according to actual applications so that the structure is simple, the maintenance is convenient, the layout is beautiful, and the cost is low.
- This embodiment further provides an excavator, and the excavator includes the hydraulic variable pump set.
- the excavator in this embodiment is a crawler excavator.
- the oil supplement component 2 provides pilot oil for the first slide valve 12 and the first control valve 13 , and at the same time, the hydraulic pump provides hydraulic oil for the first control valve 13 .
- the first control valve 13 selects the pilot oil or the hydraulic oil as output oil based on the magnitudes of the forces applied by the pilot oil and the hydraulic oil. Since an oil outlet of the first control valve 13 is in communication with the rodless cavity 1123 of the variable cylinder 112 through the first slide valve 12 , the oil in the rodless cavity 1123 is the pilot oil provided by the oil supplement component 2 or the hydraulic oil provided by the variable pump 111 .
- the valve element of the first slide valve 12 is controlled to move toward the right.
- the opening degree of the first slide valve 12 along a direction in which the oil in the rodless cavity 1123 returns the fuel tank 3 through the first slide valve 12 gradually becomes larger; and the opening degree of the first slide valve 12 along a direction in which the oil enters the rodless cavity 1123 from the first slide valve 12 becomes smaller. Therefore, the oil pressure in the rodless cavity 1123 gradually decreases.
- the force applied by the oil in the rod cavity 1122 on the piston of the variable cylinder 112 is greater than the force applied by the oil in the rodless cavity 1123 on the piston.
- variable cylinder 112 is mechanically connected to the pilot cavity 122 of the first slide valve 12 . Therefore, in this case, the piston moves toward the right, the swing angle of the swash plate 1111 is increased, and at the same time, the valve element of the first slide valve 12 is driven to move toward the right so that the effect of adjusting the output displacement of the variable pump 111 can be achieved.
- the hydraulic variable pump set integrates the variable pump 111 , the variable cylinder 112 , the first control valve 13 , and the first slide valve 12 so that advantages such as a small structure and volume, easy to use, reduced external control structures, and reduced cost can be achieved.
Abstract
Description
- The present disclosure relates to the technical field of hydraulic pumps, for example, to a hydraulic variable pump set and an excavator.
- Patent CN105113570A discloses a hydraulic component configuration of an excavator. The hydraulic oil provided by a main pump enters a negative flux feedback valve after passing through a main control valve, and a pressure signal is generated through an orifice of the negative flux feedback valve. The pressure signal controls a displacement adjustment mechanism of the main pump to adjust a flux of the main pump.
- Patent CN104480991A discloses a hydraulic pump control circuit of an excavator. A first variable pump controls the change in the relationship between outlet pressure and displacement through a first variable pump adjustment mechanism, and a second variable pump controls the change in the relationship between outlet pressure and displacement through a second variable pump adjustment mechanism. Each of the first variable pump adjustment mechanism and the second variable pump adjustment mechanism includes four control signals, where a power curve of a variable pump is controlled by three signals, that is, first variable pump outlet pressure, second variable pump outlet pressure, and a power control signal; and displacement of the variable pump is controlled by a fourth control signal. The positions of a movable arm cylinder, a stick cylinder, and a bucket cylinder are determined by a movable arm cylinder displacement sensor, a stick cylinder displacement sensor, a bucket cylinder displacement sensor, the first variable pump outlet pressure, and the second variable pump outlet pressure; based on the above, the first variable pump and the second variable pump are controlled.
- In the preceding solutions, the displacement of the variable pump is controlled through a feedback signal of an external control system. In this manner, the control system is complicated in structure and high in cost, the follow-up maintenance is complicated, and the system is large in volume and takes up a large space.
- The present disclosure provides a hydraulic variable pump set and an excavator. In this manner, a structure configured to control output displacement of a variable pump can be integrated with the variable pump, and multiple control components can be integrated so that different control functions can be achieved, and advantages such as a simple structure and a small volume can be achieved.
- An embodiment provides a hydraulic variable pump set. The hydraulic variable pump set includes a pump body component and an oil supplement component. The pump body component includes a pump body, a first slide valve, and a first control valve. The first slide valve includes a spring end and a pilot cavity, and the first control valve is provided with an oil inlet A, an oil inlet B, and an oil outlet T. The pump body includes a variable pump and a variable cylinder. The variable pump includes a swash plate, the variable cylinder includes a rod cavity and a rodless cavity, the variable cylinder is mechanically connected to the spring end and the swash plate, and the oil supplement component is in communication with the pilot cavity. The variable pump is in communication with the oil inlet A of the first control valve, the oil supplement component is in communication with the oil inlet B of the first control valve, the oil outlet T of the first control valve is in communication with the rod cavity, and the rodless cavity is in communication with the oil outlet T of the first control valve through the first slide valve.
- An embodiment further provides an excavator, and the excavator includes the hydraulic variable pump set.
-
FIG. 1 is a structure diagram of a working principle of a hydraulic variable pump set according to an embodiment of the present disclosure; and -
FIG. 2 is a structure diagram of the hydraulic variable pump set according to an embodiment of the present disclosure. -
-
- 1 pump body component
- 11 pump body
- 111 variable pump
- 1111 swash plate
- 112 variable cylinder
- 1121 piston rod
- 1122 rod cavity
- 1123 rodless cavity
- 12 first slide valve
- 121 pilot cavity
- 122 spring end
- 13 first control valve
- 14 feedback rod
- 2 oil supplement component
- 21 oil supplement pump
- 211 oil outlet of the oil supplement pump
- 22 overflow valve
- 23 filter
- 3 fuel tank
- 4 electronically-controlled pressure relief component
- 41 solenoid valve
- 42 oil inlet
- 43 oil outlet
- 5 failure-safety component
- 51 second control valve
- 6 pressure cutoff component
- 61 third control valve
- 611 pilot end
- As shown in
FIGS. 1 and 2 , this embodiment provides a hydraulic variable pump set. The hydraulic variable pump set includes apump body component 1, anoil supplement component 2, an electronically-controlled pressure relief component 4, a failure-safety component 5, and a pressure cutoff component 6. - The
pump body component 1 includes apump body 11, afirst slide valve 12, and afirst control valve 13. Thepump body 11 includes a variable pump 111 and avariable cylinder 112. In this embodiment, the variable pump 111 is a one-way variable pump, an oil inlet of the variable pump 111 is in communication with afuel tank 3, an oil outlet of the variable pump 111 is connected to an oil inlet A of thefirst control valve 13, theoil supplement component 2 is in communication with an oil inlet B of thefirst control valve 13, an oil outlet T of thefirst control valve 13 is in communication with arod cavity 1122 of thevariable cylinder 112 through one pipeline, and arodless cavity 1123 of thevariable cylinder 112 is in communication with the oil outlet T and thefuel tank 3 through thefirst slide valve 12. - Hydraulic oil provided by the
oil supplement component 2 for thefirst control valve 13 is used as control pilot oil of thefirst control valve 13, and the variable pump 111 also provides oil for thefirst control valve 13. Thefirst control valve 13 is used as a selection valve, and one of the hydraulic oil provided by theoil supplement component 2 or the hydraulic oil provided by the variable pump 111 whose pressure is relatively high is selected as a control oil source of thefirst control valve 13. - The
first control valve 13 is a shuttle valve and may also be a two-position two-way solenoid valve. - The
variable cylinder 112 is mechanically connected to apilot cavity 122 of thefirst slide valve 12 and a swash plate 111 of the variable pump 111. In an embodiment, apiston rod 1121 of thevariable cylinder 112 is mechanically connected to the swash plate 111 of the variable pump 111, the swash plate 111 of the variable pump 111 is connected to afeedback rod 14, and thefeedback rod 14 is connected to thepilot cavity 122 of thefirst slide valve 12. The movement of thevariable cylinder 112 acts on thepilot cavity 121 through thefeedback rod 14. Thepilot cavity 121 of thefirst slide valve 12 is in communication with theoil supplement component 2. - The
oil supplement component 2 provides pilot oil for thefirst slide valve 12. The pilot oil provided by theoil supplement component 2 pushes a valve element of thefirst slide valve 12 to move. - The oil outlet of the variable pump 111 is in communication with an external hydraulic control system through a port P1 in
FIG. 1 so that various movements of an excavator can be controlled. - In the case where the
pump body component 1 is working and output displacement of the variable pump 111 is at a stable value, the valve element of thefirst slide valve 12 is at a preset position, that is, the pressure applied by the pilot oil on one side of the valve element of thefirst slide valve 12 is the same as the pressure applied by a spring on the other side of the valve element of thefirst slide valve 12. In this case, the pressure of therod cavity 1122 of thevariable cylinder 112 is balanced with the pressure of therodless cavity 1123 of thevariable cylinder 112. - In the case where the
first slide valve 12 is in an initial state, the spring of thefirst slide valve 12 is compressed, and the valve element of thefirst slide valve 12 is at a leftmost position. In this case, the movement of thefeedback rod 14 toward the left always changes the compression amount of the spring, and the spring is not in a stretched state. - In the case where the displacement of the variable pump 111 needs to be adjusted, for example, in the case where the displacement of the variable pump 111 needs to be increased, the
oil supplement component 2 is controlled to provide the pilot oil for thepilot cavity 121 at a right end of thefirst slide valve 12, and the pressure in thepilot cavity 121 increases. In this case, the valve element of thefirst slide valve 12 moves toward the left. If the pressure of the hydraulic oil output from the oil outlet of the variable pump 111 is greater than the pressure of the hydraulic oil provided by theoil supplement component 2, a valve element of thefirst control valve 13 moves upward, and the path on which the hydraulic oil provided by the variable pump 111 passes through thefirst control valve 13 is from the oil inlet A to the oil outlet T. - The oil outlet T of the
first control valve 13 is branched to therod cavity 1122 and therodless cavity 1123 of thevariable cylinder 112 through pipelines, that is, the oil outlet T of thefirst control valve 13 is directly in communication with therod cavity 1122 of thevariable cylinder 112 through a first branch, and the oil outlet T of thefirst control valve 13 is in communication with therodless cavity 1123 of thevariable cylinder 112 through an internal passage of thefirst slide valve 12 on a second branch. - Since the
first slide valve 12 is a servo valve, the movement of the valve element of thefirst slide valve 12 affects the opening degree of a valve port. In the case where the valve element of thefirst slide valve 12 moves toward the left, the opening degree of an oil port on thefirst slide valve 12 along a direction in which the hydraulic oil enters therodless cavity 1123 becomes smaller, the opening degree of an oil port on therodless cavity 1123 along a direction in which the hydraulic oil flows from thefirst slide valve 12 to thefuel tank 3 becomes larger, and the pressure in therodless cavity 1123 becomes lower. In this case, a force applied by the hydraulic oil in therod cavity 1122 of thevariable cylinder 112 on a piston is greater than a force applied by the hydraulic oil in therodless cavity 1123 on the piston, and the piston A is pushed to move toward the right. In addition, the swash plate 111 is pushed through thepiston rod 1121. In this case, a swing angle of the swash plate 111 can be increased, the displacement of the variable pump 111 can be increased, the swash plate 111 drives thefeedback rod 14, and thefeedback rod 14 acts on thepilot cavity 122 so that the valve element of thefirst slide valve 12 moves toward the right. In the process of constant adjustment of the pressure in therod cavity 1122 and the pressure in therodless cavity 1123 of thevariable cylinder 112, therodless cavity 1123 and therod cavity 1122 reach a balanced state, and the valve element of thefirst slide valve 12 is stabilized at a preset position again. In this case, the displacement of the variable pump 111 has a stable output. - One of a pilot oil source provided by the
oil supplement component 2 or the hydraulic oil provided by the variable pump 111 whose pressure is relatively high is used as the control oil source of thefirst control valve 13. Under normal circumstances, an outlet P1 of the variable pump 111 is connected to an external load. Therefore, in the case where the variable pump 111 is working, the pressure generated in a pipeline between the variable pump 111 and thefirst control valve 13 is greater than the pressure of the pilot oil provided by theoil supplement component 2, and the hydraulic oil provided by the variable pump 111 is used as control oil of thefirst control valve 13. - However, when the variable pump 111 is working, if the pipeline between the variable pump 111 and the
first control valve 13 cannot generate oil pressure capable of pushing the valve element of thefirst control valve 13 to move, oil cannot enter the oil inlet A (for example, when the equipment is always in a slipping state, since the pressure in the hydraulic variable pump set is determined by the load, in this case, if the pressure cannot be established between the variable pump 111 and the first control valve 13); and if the output displacement of the variable pump 111 needs to be adjusted, since pressure cannot be established in the pipeline between the variable pump 111 and thefirst control valve 13, hydraulic oil output from the variable pump 111 cannot flow to thevariable cylinder 112 through thefirst control valve 13, the hydraulic oil in therodless cavity 1123 and therod cavity 1122 in thevariable cylinder 112 basically does not change, and the variable displacement of the variable pump 111 cannot be achieved. In this case, theoil supplement component 2 is used as the control oil source of thefirst control valve 13, hydraulic oil in theoil supplement component 2 is divided into the first branch and the second branch after passing through the oil inlet B and the oil outlet T of thefirst control valve 13, the hydraulic oil is provided for therodless cavity 1123 of thevariable cylinder 112 through the first branch, and the hydraulic oil is provided for therod cavity 1122 through the second branch; after the hydraulic oil is provided for thevariable cylinder 112, thepiston rod 1121 starts to move; and finally thepiston rod 1121 of thevariable cylinder 112 reaches a balanced state again. - In the adjustment and balancing process of the piston of the
variable cylinder 112, the swash plate 111 of the variable pump 111 moves with thepiston rod 1121, and thefeedback rod 14 is driven by the swash plate 111 to move. When the valve element of thefirst slide valve 12 is in a stable state, the displacement of the variable pump 111 remained stable again. - An
oil inlet 42 of the electronically-controlled pressure relief component 4 is in communication with theoil supplement component 2, anoil outlet 43 of the electronically-controlled pressure relief component 4 is in communication with thepump body component 1, and the electronically-controlled pressure relief component 4 may control the pressure of the pilot oil source provided by theoil supplement component 2 for thepump body component 1. - In an embodiment, the electronically-controlled pressure relief component 4 includes a
solenoid valve 41, and the pressure of the hydraulic oil output to thepump body component 1 is controlled by thesolenoid valve 41. In this embodiment, thesolenoid valve 41 is an electronically-controlled proportional pressure relief valve. An output end of thesolenoid valve 41 is connected to thepilot cavity 121 of thefirst slide valve 12. When the control system sends out a current signal, thesolenoid valve 41 starts to work, and input pressure of thesolenoid valve 41 comes from theoil supplement component 2. One side of thesolenoid valve 41 is provided with a control terminal, and an input current signal enables the control terminal to push the valve element inside thesolenoid valve 41 to move so that the opening degree of an oil circuit in thesolenoid valve 41 can be adjusted, and thus the pressure of the hydraulic oil at the outlet of thesolenoid valve 41 can be adjusted. In an embodiment, outlet pressure of thesolenoid valve 41 is proportional to the input current signal, that is, the pressure of the hydraulic oil at the outlet of thesolenoid valve 41 increases as the current increases, showing a linear proportional relationship. - In addition, in this embodiment, a failure-safety component 5 is disposed in a pipeline between the electronically-controlled pressure relief component 4 and the
pump body component 1, the failure-safety component 5 is a pilot control valve, and the working state of the failure-safety component 5 is controlled by the electronically-controlled pressure relief component 4. In the case where the electronically-controlled pressure relief component 4 is working, theoil supplement component 2 provides oil for thepilot cavity 121 of thefirst slide valve 12 through the electronically-controlled pressure relief component 4 and the failure-safety component 5. In the case where the electronically-controlled pressure relief component 4 is not working, theoil supplement component 2 provides oil for thepilot cavity 121 of thefirst slide valve 12 through the failure-safety component 5. - The failure-safety component 5 includes a
second control valve 51. In an embodiment, the output end of thesolenoid valve 41 is in communication with an oil port A of thesecond control valve 51 and is in communication with a pilot cavity of thesecond control valve 51, and theoil supplement component 2 is in communication with an oil port B of thesecond control valve 51. In the case where the electronically-controlled pressure relief component 4 is not working, theoil supplement component 2 provides oil for thepilot cavity 121 of thefirst slide valve 12 through the failure-safety component 5. In this case, no pilot oil exists in the pilot cavity of thesecond control valve 51, thesecond control valve 51 is in a right working state, and the oil port B of thesecond control valve 51 is always in communication with thepilot cavity 121 of thefirst slide valve 12. The oil is divided into two paths after entering thesecond control valve 51 from the oil port B, where one path is in communication with thepilot cavity 121 of thefirst slide valve 12, and the other path is in communication with the fuel tank; in addition, the path in communication with the fuel tank is provided with an orifice. In the case where the electronically-controlled pressure relief component 4 is working, part of the hydraulic oil from an outlet of the electronically-controlled pressure relief component 4 is used as pilot oil and acts on one end of thesecond control valve 51 so that thesecond control valve 51 is in a left working state. In this case, the oil port B is closed, and the oil in theoil supplement component 2 may only communicate with thesecond control valve 51 through the electronically-controlled pressure relief component 4 and then communicate with thepilot cavity 121 of thefirst slide valve 12. Through the preceding structure, thepilot cavity 121 of thefirst slide valve 12 is in communication with theoil supplement component 2, and the control pressure of thepilot cavity 121 of thefirst slide valve 12 is adjusted by different working positions of the electronically-controlled pressure relief component 4 and the failure-safety component 5. In this embodiment, thesecond control valve 51 is a two-position four-way servo slide valve, and oil can pass through thesecond control valve 51 in two directions. - In the case where the displacement of the variable pump 111 is large and the system is too high in pressure, the output power of the hydraulic variable pump set can be reduced by reducing the displacement of the variable pump 111 so that engine failure and energy loss caused by excessive power can be avoided. Therefore, a pressure cutoff component 6 is provided. The pressure cutoff component 6 is connected to a pipeline between the
first control valve 13 and thefirst slide valve 12. In the case where the output pressure of the variable pump 111 reaches a preset pressure threshold, the pressure cutoff component 6 operates so that therod cavity 1122 of thevariable cylinder 112 is in communication with therodless cavity 1123 of thevariable cylinder 112. - The pressure cutoff component 6 includes a
third control valve 61, where thethird control valve 61 is a two-position three-way servo slide valve, the oil outlet T of thefirst control valve 13 may simultaneously communicate with apilot end 611 of thethird control valve 61 and an oil port A of thethird control valve 61, and an oil port T of thethird control valve 61 is in communication with thefirst slide valve 12. In the case where the displacement of the variable pump 111 is not the maximum (that is, thefirst slide valve 12 is not at the leftmost position) and thethird control valve 61 does not operate, therodless cavity 1123 of thevariable cylinder 112 is always in communication with thefuel tank 3 through thefirst slide valve 12 and thethird control valve 61. In this working state, therodless cavity 1123 of thevariable cylinder 112 is in communication with thefuel tank 3 through an internal passage of thesecond control valve 12, the oil port T of thethird control valve 61, and the oil port B of thethird control valve 61. In the case where thethird control valve 61 operates, therod cavity 1122 of thevariable cylinder 112 may communicate with therodless cavity 1123 of the variable pump 111 through thethird control valve 61 and thefirst slide valve 12. In this case, if a valve element of thethird control valve 61 is not completely in the left working state, therodless cavity 1123 is still in communication with thefuel tank 3. - At an initial position, the
third control valve 61 is at the right working state. In this case, therod cavity 1122 of thevariable cylinder 112 does not communicate with therodless cavity 1123 of thevariable cylinder 112. However, in this case, if the variable pump 111 is in a stable displacement state, therodless cavity 1123 of thevariable cylinder 112 is in communication with the fuel tank through thefirst slide valve 12 and thethird control valve 61. If the variable pump 111 is applied to an excavator, in the case where the displacement of the variable pump 111 is very large and the movement of the excavator is blocked, a port P1 of the hydraulic variable pump set in this embodiment is connected to an external load system, the external load system controls the pressure in pipelines of the hydraulic variable pump set in this embodiment, and the pressure is determined by the external load system. In the case where the pressure in the hydraulic variable pump set increases to the preset pressure threshold of thethird control valve 61, the pressure cutoff component 6 takes effect, that is, the valve element of thethird control valve 61 moves. The valve element of thethird control valve 61 moves so that therodless cavity 1123 is in communication with therod cavity 1122, and the displacement of the variable pump 111 can be controlled through the adjustment of thevariable cylinder 112. The displacement of the variable pump 111 is controlled so that the purpose of controlling the output power of the variable pump 111 can be achieved. In an embodiment, hydraulic oil from the oil outlet T of thefirst control valve 13 is used as pilot oil of thethird control valve 61 and acts on thepilot end 611 of thethird control valve 61, and the valve element of thethird control valve 61 is pushed to move toward the right. In this case, therodless cavity 1123 is in communication with therod cavity 1122. - The opening degree of the valve element of the
third control valve 61 along a direction in which the hydraulic oil flows to therodless cavity 1123 becomes larger, and the opening degree of the valve element of thethird control valve 61 along a direction in which the hydraulic oil returns to thefuel tank 3 from therodless cavity 1123 becomes smaller. That is, the high-pressure oil passing through therod cavity 1122 flows to therodless cavity 1123 of thevariable cylinder 112 through the oil port A and the oil port T of the third control valve and thefirst slide valve 12. Therod cavity 1122 and therodless cavity 1123 are high-pressure oil, and the hydraulic oil returning to the fuel tank causes less pressure drop in therodless cavity 1123. Therefore, the pressure applied by the hydraulic oil in therodless cavity 1123 on the piston is gradually greater than the pressure applied by the hydraulic oil in therod cavity 1122 on the piston, and the piston is pushed to move toward the left. In this case, the swing angle of the swash plate 111 becomes smaller, and the output displacement of the variable pump 111 becomes the small displacement until the two cavities are in the balanced state, and the output displacement of the variable pump 111 is stable again. - The
first slide valve 12 and thethird control valve 61 are used as variable control valves of the variable pump 111, the variable direction and variable degree of the variable pump 111 are controlled according to the pressure of the pilot oil, and the magnitudes of the openings of thefirst slide valve 12 and thethird control valve 61 are in a linear proportional relationship with the variable degree of the variable pump 111. - The
oil supplement component 2 includes an oil supplement pump 21 and anoverflow valve 22. Anoil outlet 211 of the oil supplement pump 21 is connected to thepump body component 1, the failure-safety component 5, and the pressure cutoff component 6. The oil supplement pump 21 provides pilot oil for the preceding multiple components. In an embodiment, the oil supplement pump 21 is in communication with thesolenoid valve 41, thefirst control valve 13, and thesecond control valve 51 through afilter 23. - The
overflow valve 22 is in communication with and in parallel with the oil supplement pump 21, and the oil supplement pump 21 is in a form of a quantitative gear pump and is integrated with the overflow valve. The output flux of the quantitative gear pump is constant, while the system controls the oil to continuously change according to the requirements. Therefore, based on a case where it is ensured that the pilot oil required by the multiple components of the system is provided, the rest of the hydraulic oil is overflowed to thefuel tank 3 through theoverflow valve 22, and part of the hydraulic oil is overflowed to an oil suction port of the oil supplement pump 21 so that the balance of system cooling and energy saving can be achieved. - In this embodiment, the hydraulic variable pump set includes two
pump body components 1, and eachpump body component 1 corresponds to one electronically-controlled pressure relief component 4, one failure-safety component 5, and one pressure cutoff component 6. In an embodiment, eachpump body component 1 is correspondingly connected to onesolenoid valve 41, onesecond control valve 51, and onethird control valve 61. Variable pumps 111 of the twopump bodies 11 communicate with each other, but the variable pumps 111 of the twopump bodies 11 are controlled independently of each other. An output end of the variable pump 111 of onepump body 11 is provided with a port P1, and an output end of the variable pump 111 of theother pump body 11 is provided with a port P2, where each of the P2 port and the P1 port is configured to communicate with the external hydraulic control system so that various movements of the excavator can be achieved. - The variable pumps 111 of the two
pump body components 1 and the oil supplement pump 21 of oneoil supplement component 2 are connected in series and in sequence. Drive shafts of the two variable pumps 111 and a drive shaft of the oil supplement pump 21 are connected in series and in sequence, and the same engine (motor) is shared for driving so that a triple pump structure is formed. The twopump body components 1, the two electronically-controlled pressure relief components 4, the two failure-safety components 5, and the two pressure cutoff components 6 all share oneoil supplement component 2, and theoil supplement component 2 provides pilot oil. The two electronically-controlled pressure relief components 4 can individually control different oil pressure outputs. - In this embodiment, through the combination of the
solenoid valve 41 and the slide valve, multiple functions of the main hydraulic pump of the excavator can be achieved, and the multiple functions include an electronic proportional control function, a pressure cutoff function, a failure-safety function, and an oil supplement function. Power control can be achieved by combining with the electronic control component. Advantages such as sound functions, a reasonable structure, simple control, and high reliability can be achieved so that the use requirements of the excavator can be fully satisfied. - In this embodiment, in the case where the electrical control system of the excavator fails, the hydraulic pump can automatically reach the maximum displacement so that it is ensured that the excavator can perform work and walking functions.
- In this embodiment, the component arrangement is adopted, and functional components can be added or removed according to actual applications so that the structure is simple, the maintenance is convenient, the layout is beautiful, and the cost is low.
- This embodiment further provides an excavator, and the excavator includes the hydraulic variable pump set. The excavator in this embodiment is a crawler excavator.
- In this embodiment, the
oil supplement component 2 provides pilot oil for thefirst slide valve 12 and thefirst control valve 13, and at the same time, the hydraulic pump provides hydraulic oil for thefirst control valve 13. Thefirst control valve 13 selects the pilot oil or the hydraulic oil as output oil based on the magnitudes of the forces applied by the pilot oil and the hydraulic oil. Since an oil outlet of thefirst control valve 13 is in communication with therodless cavity 1123 of thevariable cylinder 112 through thefirst slide valve 12, the oil in therodless cavity 1123 is the pilot oil provided by theoil supplement component 2 or the hydraulic oil provided by the variable pump 111. - If the output displacement of the variable pump 111 needs to be increased, the valve element of the
first slide valve 12 is controlled to move toward the right. In this case, the opening degree of thefirst slide valve 12 along a direction in which the oil in therodless cavity 1123 returns thefuel tank 3 through thefirst slide valve 12 gradually becomes larger; and the opening degree of thefirst slide valve 12 along a direction in which the oil enters therodless cavity 1123 from thefirst slide valve 12 becomes smaller. Therefore, the oil pressure in therodless cavity 1123 gradually decreases. In this case, the force applied by the oil in therod cavity 1122 on the piston of thevariable cylinder 112 is greater than the force applied by the oil in therodless cavity 1123 on the piston. Thevariable cylinder 112 is mechanically connected to thepilot cavity 122 of thefirst slide valve 12. Therefore, in this case, the piston moves toward the right, the swing angle of theswash plate 1111 is increased, and at the same time, the valve element of thefirst slide valve 12 is driven to move toward the right so that the effect of adjusting the output displacement of the variable pump 111 can be achieved. - The hydraulic variable pump set integrates the variable pump 111, the
variable cylinder 112, thefirst control valve 13, and thefirst slide valve 12 so that advantages such as a small structure and volume, easy to use, reduced external control structures, and reduced cost can be achieved.
Claims (20)
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PCT/CN2018/123851 WO2020132934A1 (en) | 2018-12-26 | 2018-12-26 | Hydraulic variable pump set and excavator |
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US20220065272A1 true US20220065272A1 (en) | 2022-03-03 |
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US (1) | US11280357B1 (en) |
JP (1) | JP7200385B2 (en) |
KR (1) | KR102577950B1 (en) |
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2018
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- 2018-12-26 JP JP2021538435A patent/JP7200385B2/en active Active
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CN113227587A (en) | 2021-08-06 |
KR102577950B1 (en) | 2023-09-14 |
KR20210105423A (en) | 2021-08-26 |
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JP7200385B2 (en) | 2023-01-06 |
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