CN111980977A - Cross power control valve for duplex hydraulic pump and duplex hydraulic pump - Google Patents
Cross power control valve for duplex hydraulic pump and duplex hydraulic pump Download PDFInfo
- Publication number
- CN111980977A CN111980977A CN202010728790.0A CN202010728790A CN111980977A CN 111980977 A CN111980977 A CN 111980977A CN 202010728790 A CN202010728790 A CN 202010728790A CN 111980977 A CN111980977 A CN 111980977A
- Authority
- CN
- China
- Prior art keywords
- power
- oil pressure
- hydraulic pump
- valve core
- variable
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
-
- 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
-
- 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
- F15B15/08—Characterised by the construction of the motor unit
- F15B15/14—Characterised by the construction of the motor unit of the straight-cylinder type
- F15B15/1409—Characterised by the construction of the motor unit of the straight-cylinder type with two or more independently movable working pistons
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Fluid-Driven Valves (AREA)
Abstract
The embodiment of the invention discloses a cross power control valve for a duplex hydraulic pump and the duplex hydraulic pump, wherein a valve core of the cross power control valve is of a two-stage step structure and comprises a first step part and a second step part; an annular groove is formed in the outer circle of the first step part and is used for communicating with an oil return port of the duplex hydraulic pump, pilot oil pressure Ps acts on the end face of the first step part, and average outlet oil pressure Pm of the duplex hydraulic pump acts on the step faces of the first step part and the second step part; and a cross power control valve for discharging the pilot oil pressure Ps and the outlet average oil pressure Pm leaked to the annular groove through the annular groove, thereby blocking interference of the pilot oil pressure Ps and the outlet average oil pressure Pm. The embodiment of the invention solves the problems that the traditional valve core with a three-level step structure is difficult to process and manufacture, the phenomenon of clamping stagnation of the valve core is difficult to avoid, certain influence is caused on control precision, and the like.
Description
Technical Field
The invention relates to the technical field of hydraulic control, in particular to a cross power control valve for a duplex hydraulic pump and the duplex hydraulic pump.
Background
The constant power control of the duplex hydraulic pump needs to apply the outlet pressure of the main pump and the slave pump on respective power valve cores, so that the power of an engine can be fully utilized like a full power system, and the output flow can be adjusted according to the load conditions of the main pump and the slave pump like a sub-power system, and the control mode is cross power control.
In order to realize the power-level gear shifting, a path of external control pressure Ps is also arranged on the power valve core and is generally provided by an electromagnetic pressure reducing valve. Like this, total three routes control pressure effect on the power valve core, prior art need be for tertiary step with the case design, narrow and small space, both will guarantee fit clearance and axiality, will prevent again that the atress of three routes oil pressure influence case because of leaking the interference, and this brings certain difficulty for the manufacturing of power valve core and valve opening, is difficult to avoid the case to appear the jamming phenomenon and brings certain influence to control accuracy.
Disclosure of Invention
The purpose of the invention is as follows: the cross power control valve for the duplex hydraulic pump and the duplex hydraulic pump are provided to solve the problems that the existing valve core with a three-level step structure is high in processing and manufacturing difficulty, clamping stagnation phenomenon of the valve core is difficult to avoid, certain influence is caused on control precision, and the like.
The technical scheme of the invention is as follows:
the embodiment of the invention provides a cross power control valve for a duplex hydraulic pump, wherein a valve core of the cross power control valve is of a two-stage step structure and comprises a first step part and a second step part;
the outer circle of the first step part is provided with an annular groove, the annular groove is used for communicating with an oil return port of the duplex hydraulic pump, a pilot oil pressure Ps acts on the end face of the first step part, and an outlet average oil pressure Pm of the duplex hydraulic pump acts on the step faces of the first step part and the second step part;
and the cross power control valve is used for discharging the pilot oil pressure Ps leaked to the annular groove and the outlet average oil pressure Pm through the annular groove so as to block the interference of the pilot oil pressure Ps and the outlet average oil pressure Pm.
Alternatively, in the cross power control valve for a duplex hydraulic pump as described above, the duplex hydraulic pump includes a main pump and a slave pump, an outlet oil pressure of the main pump is P1, an outlet oil pressure of the slave pump is P2, and an outlet average oil pressure Pm is an oil pressure after the outlet oil pressure P1 and the outlet oil pressure P2 are throttled and merged; pm ═ P1+ P2)/2.
Optionally, in the cross power control valve for a duplex hydraulic pump as described above, the spool is a negative flow spool 10; the crossover power control valve further comprises: the variable valve comprises a valve body 13, a variable piston 20, a negative flow valve sleeve 11, a power valve core 7, a power valve sleeve 6, a positioning pin 14 and a deflector rod 15, wherein the variable piston is arranged in the valve body 13;
the negative flow valve sleeve 11 is provided with two-stage step holes for sleeving the negative flow valve core 10 with a two-stage step structure, and the negative flow valve sleeve 11 is provided with an oil return hole corresponding to the position of the annular groove for guiding oil;
the power valve core 7 is embedded into the power valve sleeve 6, one end of a deflector rod 15 is movably arranged on the power valve sleeve 6 through a positioning pin 14, so that the deflector rod can rotate along the positioning pin 14, the other end of the deflector rod 15 is connected with the top end of the regulator through a variable rod in a variable piston 20, and the deflector rod is driven to rotate by the regulator; one end face of the power valve core 7 is in contact with the end face of a second step part in the negative flow valve core 10, a spring 9 is sleeved on the periphery of a contact part of the power valve core 7 and the negative flow valve core 10, the spring 9 is positioned between the power valve sleeve 6 and the negative flow valve sleeve 11, so that the power valve sleeve 6 is attached to a deflector rod 15 to eliminate the invalid stroke of the power valve sleeve 6, the other end of the power valve core 7 is in contact with the spring seat 4 through a steel ball 5, and a spring assembly arranged on the spring seat 4 is used for providing pre-tightening force for the power valve core 7 and the negative flow valve core 10 to perform power adjustment on; wherein, the negative flow valve core 10, the flow valve sleeve 11, the power valve core 7 and the power valve sleeve 6 are positioned on the same axis.
Optionally, in the above-mentioned crossed power control valve for a duplex hydraulic pump, the power valve spool 7 and the power valve sleeve 6 are provided with an oil return port, an oil outlet A3/a4, and a Δ P port which is communicated with the oil outlet and can be communicated with the oil path of the variable piston 20;
when the average oil pressure Pm of the outlet is smaller than the oil pressure threshold value, the oil outlets (A3/A4) of the power valve core 7 and the power valve sleeve 6 are communicated with the oil path of the variable piston 20 through a port delta P;
when the outlet average oil pressure Pm is increased to an oil pressure threshold value, the sum of the outlet average oil pressure Pm and the pilot oil pressure Ps is larger than the pretightening force of the spring assembly, so that the negative flow valve core 10 pushes the power valve core 7, the delta P port is closed, the oil return port is communicated with the oil path of the variable piston 20, the variable piston 20 drives the regulator to move, the shift lever 15 is driven to rotate, the power valve sleeve 6 is pushed, the power valve core and the power valve sleeve are in a dynamic balance position, and the oil outlet (A3/A4) is filled with oil.
Optionally, in the cross power control valve for a duplex hydraulic pump as described above, the spring assembly includes a primary variable spring 16 and a secondary variable spring 17, and the cross power control valve further includes: the device comprises a first locking nut 1, a primary variable adjusting threaded sleeve 2, a secondary variable adjusting screw 3, a threaded sleeve 18 and a second locking nut 19;
one end of the secondary variable adjusting screw 3 is arranged opposite to the end face of the spring seat 4, and a secondary variable spring 17 is arranged between the secondary variable adjusting screw 3 and the spring seat 4; the primary variable adjusting threaded sleeve 2 is sleeved at one end of the secondary variable adjusting screw 3, a primary variable spring 16 is arranged between the primary variable adjusting threaded sleeve 2 and the spring seat 4, the outer end of the primary variable adjusting threaded sleeve 2 is fixed through a threaded sleeve 18 and a second locking nut 19, and the outer end of the secondary variable adjusting screw 3 is fixed through a first locking nut 1.
Optionally, in the cross power control valve for a duplex hydraulic pump as described above, a negative flow spring 12 is disposed between the valve body 13 and the negative flow valve sleeve 11, and a pilot oil port is disposed on the valve body 13, and is used for providing a pilot pressure Pn to the negative flow valve sleeve 11 through the pilot oil port, so that the negative flow valve sleeve 11 pushes the negative flow spool 10 and the power spool 7 to move, thereby moving the variable piston 20 from the small end to the large section.
The embodiment of the invention also provides a duplex hydraulic pump, which comprises: a main pump, a slave pump, a pilot pump, and two variable pistons and two crossover power control valves as described in any of the above in cooperation with the main pump and the slave pump, respectively;
the outlet oil pressure P1 of the main pump is connected to the small end of the corresponding variable piston and is connected to the large end of the variable piston through a cross power control valve, the outlet oil pressure P2 of the slave pump is connected to the small end of the corresponding variable piston and is connected to the large end of the variable piston through the cross power control valve, and the oil pressure Pm after the outlet oil pressure P1 of the main pump and the outlet oil pressure P2 of the slave pump are throttled and converged respectively act on the step surfaces of valve cores of the two cross power control valves;
the pilot oil pressure Ps supplied from the pilot pump acts on the end surfaces of the first step portions in the spools of the two cross power control valves, respectively.
Optionally, in the dual hydraulic pump as described above, the spool is a negative flow spool;
the duplex hydraulic pump is used for enabling the power valve core and the power valve sleeve to be communicated with the variable piston oil path at the initial positions of the power valve core and the power valve sleeve, so that outlet oil pressure P1/P2 acts on two ends of the variable piston at the same time, the variable piston is forced to move from the large end to the small end through the area difference of the variable piston, and the main pump and the slave pump are both in the maximum displacement state.
Alternatively, in a dual hydraulic pump as described above,
the duplex hydraulic pump is also used for increasing the average oil pressure Pm at the outlet and enabling the acting force acting on the negative flow valve core to be larger than the primary spring force of the power valve, the negative flow valve core pushes the power valve core to move so that the cavity of the large end of the variable piston is communicated with the return oil, and the small end of the variable piston always acts on the outlet oil pressure P1/P2 so that the variable piston moves from the small end to the large end and the displacement of the hydraulic pump is reduced; in the process of the movement of the variable piston, a deflector rod is driven to move, and the deflector rod drives a power valve sleeve to move, so that the power valve core and the power valve sleeve are in a dynamic balance position;
the duplex hydraulic pump is also used for continuously increasing the average oil pressure Pm at the outlet and continuously pushing the power valve core to move by the negative flow valve core when the acting force acting on the negative flow valve core is larger than the sum of the primary spring force and the secondary spring force of the power valve, so that the large-end cavity of the variable piston is communicated with the return oil again.
Alternatively, in a dual hydraulic pump as described above,
the duplex hydraulic pump is also used for enabling the negative flow valve sleeve to push the negative flow valve core and the power valve core to move together through the pilot pressure Pn acting on the negative flow valve sleeve when the duplex hydraulic pump is in a standby state, the variable piston moves from the small end to the large end until the variable piston reaches the limit position, and at the moment, the hydraulic pump is in the minimum displacement state.
The invention has the advantages that:
according to the cross power control valve for the duplex hydraulic pump and the duplex hydraulic pump, the negative flow valve core is designed into a two-stage step structure, and the annular groove for communicating with the return oil is arranged between the Pm action pressure and the Ps action pressure of the two-stage step structure, so that the valve core of the two-stage step structure not only greatly reduces the processing difficulty and the manufacturing cost, improves the control performance of the cross power valve, but also reduces the clamping stagnation risk caused by the processing difficulty, and avoids the influence on the control precision caused by the series flow of various pressure oils. Therefore, the technical scheme of the embodiment of the invention has good economic value and practical value and is worthy of market popularization and application.
Description of the drawings:
FIG. 1 is a schematic diagram of a negative flow valve cartridge of the prior art;
FIG. 2 is a schematic diagram of a cross power control valve for a duplex hydraulic pump according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of another cross power control valve for a duplex hydraulic pump according to an embodiment of the present invention;
FIG. 4 is a cross-sectional view of the cross-power control valve for the tandem hydraulic pump of FIG. 3, shown from a different perspective;
FIG. 5 is a schematic diagram of a dual hydraulic pump according to an embodiment of the present invention;
FIG. 6 is a schematic diagram of a power shift curve for a cross power control valve for a twin hydraulic pump according to an embodiment of the present invention.
The specific implementation mode is as follows:
fig. 1 is a schematic structural diagram of a negative flow valve core in the prior art, and it can be seen that the negative flow valve core is designed to be a three-step structure, which is difficult to process and high in manufacturing cost. The three-level steps are respectively acted by the pressure of P1, P2 and Ps, no annular groove is designed among P1, P2 and Ps to communicate with oil return, and the risk of oil leakage exists to influence the control precision.
In order to improve the reliability of the cross power control valve and reduce the processing difficulty and the manufacturing cost, the invention designs the three-stage step of the power valve core structure into the two-stage step, and simultaneously arranges the oil drainage channel, thereby preventing the influence of the leakage of the connected control pressure on the acting force of the valve core and improving the control precision of the cross power control valve.
In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the embodiments and features of the embodiments in the present application may be arbitrarily combined with each other without conflict.
Fig. 2 is a schematic structural diagram of a cross power control valve for a duplex hydraulic pump according to an embodiment of the present invention, and fig. 2 illustrates a valve core structure of the cross power control valve. The valve core of the cross power control valve in the embodiment of the invention is of a two-step structure and comprises a first step part and a second step part.
In the structure of the spool in the cross power control valve shown in fig. 2, an annular groove is formed in the outer circle of the first step portion, the annular groove is used for communicating with an oil return port of the duplex hydraulic pump, a pilot oil pressure Ps acts on the end face of the first step portion, and an outlet average oil pressure Pm of the duplex hydraulic pump acts on the step faces of the first step portion and the second step portion.
The working principle of the cross power control valve provided by the embodiment of the invention is as follows: the pilot oil pressure Ps and the outlet average oil pressure Pm leaking to the annular groove are discharged through the annular groove of the first step portion, thereby blocking interference between the pilot oil pressure Ps and the outlet average oil pressure Pm.
In practical application, the duplex hydraulic pump generally comprises a main pump and a slave pump, wherein the outlet oil pressure of the main pump is P1, the outlet oil pressure of the slave pump is P2, and the outlet average oil pressure Pm is the oil pressure after the outlet oil pressure P1 and the outlet oil pressure P2 are throttled and converged; pm is (P1+ P2)/2.
According to the cross power control valve for the duplex hydraulic pump, provided by the embodiment of the invention, a valve core of a core structure is designed into a two-stage step structure, pressures of Pm and Ps act on two stages of steps respectively, the Pm is an average pressure of a main pump outlet pressure P1 and a slave pump outlet pressure P2 after respective throttling confluence, an annular groove is designed between the pressures of the Pm and the Ps for communicating with return oil, oil entering the return oil after the pressures of the Pm and the Ps are in series flow is ensured, and therefore the influence of the Pm and the Ps on control precision due to series flow is avoided.
Fig. 3 is a schematic structural diagram of another cross power control valve for a duplex hydraulic pump according to an embodiment of the present invention. The valve core in the embodiment of the invention is a negative flow valve core 10; namely, the crossover power control valve further comprises: the variable valve comprises a valve body 13, a variable piston 20 arranged in the valve body 13, a negative flow valve sleeve 11, a power valve core 7, a power valve sleeve 6, a positioning pin 14, a shift lever 15 and a slide block 21.
As shown in fig. 3, in the structure of the cross power control valve, a negative flow valve sleeve 11 is provided with two-stage step holes for sleeving a negative flow valve core 10 having a two-stage step structure, and the negative flow valve sleeve 11 is provided with an oil return hole corresponding to the position of the annular groove for guiding oil.
FIG. 4 is a cross-sectional view of the cross-power control valve for the tandem hydraulic pump of FIG. 3, taken from a different perspective. Referring to fig. 3 and 4, a power valve core 7 according to an embodiment of the present invention is embedded in a power valve sleeve 6, one end of a shift lever 15 is movably disposed on the power valve sleeve 6 through a positioning pin 14, such that the shift lever can rotate along the positioning pin 14, and the other end of the shift lever 15 is connected to a top end of an adjuster through a variable rod in a variable piston 20, and the shift lever is driven by the adjuster to rotate; one end face of the power valve spool 7 is in contact with the end face of a second step part in the negative flow valve spool 10, a spring 9 is sleeved on the periphery of the contact part of the power valve spool 7 and the negative flow valve spool 10, the spring 9 is positioned between the power valve sleeve 6 and the negative flow valve sleeve 11, so that the power valve sleeve 6 is attached to a deflector rod 15 to eliminate the invalid stroke of the power valve sleeve 6, the other end of the power valve spool 7 is in contact with a spring seat 4 through a steel ball 5, and a spring assembly arranged on the spring seat 4 is used for providing pre-tightening force for the power valve spool 7 and the negative flow valve spool 10 to perform power adjustment; wherein, the negative flow valve core 10, the flow valve sleeve 11, the power valve core 7 and the power valve sleeve 6 are positioned on the same axis.
In addition, the sliding block 21 is installed between the shift lever 15 and the power valve housing 6, and when the shift lever 15 rotates, the sliding block 21 is driven to move in the axial direction of the power valve housing 6, so as to drive the axial movement of the power valve housing 6.
In practical application of the embodiment of the invention, the power valve core 7 and the power valve sleeve 6 are provided with an oil return port, an oil outlet (A3/A4) and a delta P port which is communicated with the oil outlet (A3/A4) and can be communicated with an oil path of the variable piston 20.
The working principle of the cross power control valve in the embodiment of the invention comprises the following steps: when the average outlet oil pressure Pm is smaller than the oil pressure threshold value, the oil outlets (A3/A4) of the power valve spool 7 and the power valve sleeve 6 are communicated with the oil path of the variable piston 20 through a port delta P.
The working principle of the cross power control valve in the embodiment of the invention also comprises the following steps: when the outlet average oil pressure Pm is increased to an oil pressure threshold value, the sum of the outlet average oil pressure Pm and the pilot oil pressure Ps is larger than the pretightening force of the spring assembly, so that the negative flow valve core 10 pushes the power valve core 7, the delta P port is closed, the oil return port is communicated with the oil path of the variable piston 20, the variable piston 20 drives the regulator to move, the shift lever 15 is driven to rotate, the power valve sleeve 6 is pushed, the power valve core and the power valve sleeve are in a dynamic balance position, and the oil outlet (A3/A4) is filled with oil.
In one implementation of an embodiment of the present invention, as shown in fig. 3, the spring assembly may include a primary variable spring 16 and a secondary variable spring 17; accordingly, the crossover power control valve further comprises: the device comprises a first locking nut 1, a primary variable adjusting threaded sleeve 2, a secondary variable adjusting screw 3, a threaded sleeve 18 and a second locking nut 19.
In the structure of the spring assembly shown in fig. 3, one end of the secondary variable adjusting screw 3 is arranged opposite to the end surface of the spring seat 4, and a secondary variable spring 17 is arranged between the secondary variable adjusting screw 3 and the spring seat 4; the primary variable adjusting threaded sleeve 2 is sleeved at one end of the secondary variable adjusting screw 3, a primary variable spring 16 is arranged between the primary variable adjusting threaded sleeve 2 and the spring seat 4, the outer end of the primary variable adjusting threaded sleeve 2 is fixed through a threaded sleeve 18 and a second locking nut 19, and the outer end of the secondary variable adjusting screw 3 is fixed through a first locking nut 1.
In another implementation manner of the embodiment of the present invention, as also shown in fig. 3, a negative flow spring 12 is disposed between the valve body 13 and the negative flow valve sleeve 11, and a pilot oil port is disposed on the valve body 13, and is used for providing a pilot pressure Pn to the negative flow valve sleeve 11 through the pilot oil port, so that the negative flow valve sleeve 11 pushes the negative flow valve spool 10 and the power valve spool 7 to move, and thus the variable piston 20 moves from the small end to the large section.
Based on the cross power control valve for the duplex hydraulic pump provided by the above embodiments of the present invention, an embodiment of the present invention further provides a duplex hydraulic pump, as shown in fig. 5, which is a schematic structure of a duplex hydraulic pump provided by an embodiment of the present invention. The duplex hydraulic pump provided by the embodiment of the invention can comprise: the system comprises a main pump, a slave pump, a pilot pump, two variable pistons and two cross power control valves, wherein the two variable pistons and the two cross power control valves are respectively matched with the main pump and the slave pump, and the cross power control valves are provided in any one of the above embodiments of the invention.
In the structure of the twin hydraulic pump shown in fig. 5, the outlet oil pressure P1 of the main pump is connected to the small end of the corresponding variable piston and is connected to the large end of the variable piston through the cross power control valve, the outlet oil pressure P2 of the slave pump is connected to the small end of the corresponding variable piston and is connected to the large end of the variable piston through the cross power control valve, and the main pump outlet oil pressure P1 and the slave pump outlet oil pressure P2 are throttled and converged to form an oil pressure Pm which acts on the step surfaces of the spools of the two cross power control valves, respectively.
The pilot oil pressure Ps supplied from the pilot pump in the embodiment of the present invention acts on the end surfaces of the first stepped portions in the spools of the two intersecting power control valves, respectively.
In one implementation of an embodiment of the invention, the spool of the crossover power control valve is a negative flow spool.
The working mode of the duplex hydraulic pump in the embodiment of the invention comprises the following steps: in the initial positions of the power valve core and the power valve sleeve, the power valve core and the power valve sleeve are communicated with the variable piston oil path, so that outlet oil pressure P1/P2 acts on two ends of the variable piston at the same time, the variable piston is forced to move from a large end to a small end through the area difference of the variable piston, and the main pump and the slave pump are both in the maximum displacement state.
The working mode of the duplex hydraulic pump in the embodiment of the invention also comprises the following steps: when the average outlet oil pressure Pm is increased and the acting force acting on the negative flow valve core is greater than the primary spring force of the power valve, the negative flow valve core pushes the power valve core to move, so that the cavity of the large end of the variable piston is communicated with return oil, and the small end of the variable piston always acts on the outlet oil pressure P1/P2, so that the variable piston moves from the small end to the large end, and the displacement of the hydraulic pump is reduced; in the process of the movement of the variable piston, the driving lever is driven to move, the driving lever drives the power valve sleeve to move, and the movement of the power valve sleeve enables the return oil to be closed, so that the power valve core and the power valve sleeve are in a dynamic balance position.
The working mode of the duplex hydraulic pump in the embodiment of the invention also comprises the following steps: when the average oil pressure Pm of the outlet continues to increase and the acting force acting on the negative flow valve core is greater than the sum of the primary spring force and the secondary spring force of the power valve, the negative flow valve core continues to push the power valve core to move, so that the large-end cavity of the variable piston is communicated with the return oil again.
The working mode of the duplex hydraulic pump in the embodiment of the invention also comprises the following steps: when the variable displacement hydraulic pump is in a standby state, the negative flow valve sleeve pushes the negative flow valve core and the power valve core to move together through the pilot pressure Pn acting on the negative flow valve sleeve, the variable piston moves from the small end to the large end until the variable piston reaches the limit position, and at the moment, the hydraulic pump is in the minimum displacement state.
The cross power control valve for the duplex hydraulic pump and the duplex hydraulic pump provided by the embodiment of the invention comprise a power valve core and a power valve sleeve which are used for controlling the on-off of variable piston oil, wherein the initial position of the power valve core and the power valve sleeve are in a state of enabling the variable piston to be in oil communication, pressure oil acts on two ends of the variable piston at the same time, the variable piston is forced to move from a large end to a small end due to area difference, and the two hydraulic pumps are in a maximum displacement state. The cross power control valve also comprises a negative flow valve core and a negative flow valve sleeve, wherein the negative flow valve core is a two-stage step and is respectively used for acting on the average pressure Pm after the pressure of two outlets of the duplex hydraulic pump is converged and the external control pressure Ps for power gear shifting.
When the power of the cross power control valve does not perform the gear shifting action, the external control pressure is kept constant. When the load pressure (namely P1 and P2) changes, the average pressure Pm changes, when the force acting on the negative flow valve core overcomes the primary spring force of the power valve, the negative flow valve core pushes the power valve core to move, at the moment, the large end cavity of the variable piston is communicated with return oil, and because the small end of the variable piston always acts on pressure oil, the variable piston moves from the small end to the large end, and the displacement of the hydraulic pump is reduced. Meanwhile, in the process of the movement of the variable piston, the driving rod is driven to move, and the driving rod drives the power valve sleeve to move, so that the power valve core and the power valve sleeve are in a dynamic balance position, and the process is a primary variable of the power valve. When the load pressure (P1 and P2) continues to increase and the acting force of the negative flow valve core simultaneously overcomes two spring forces of the power valve, the secondary variable of the power valve is opened at the moment, and the movement process is the same as that of the primary variable. Because the first-stage variable overcomes only one spring force, and the second-stage variable overcomes two spring forces at the same time, the slopes are different, and the two crossed broken lines form a constant power curve which is approximate to a hyperbolic curve. When the operating rod does not act, the pilot pressure Pn acts on the negative flow valve sleeve, the negative flow valve sleeve pushes the negative flow valve core and the power valve core to move together, the variable piston moves from the small end to the large end until the limit position, and at the moment, the hydraulic pump is in the minimum displacement state. If the output power of the main pump is different from that of the slave pump, the pilot pressure Pn acted on the negative flow valve core by the main pump and the slave pump is only required to be different, and therefore cross power control is achieved.
Fig. 6 is a schematic diagram of a power shift curve for a cross power control valve for a dual hydraulic pump according to an embodiment of the present invention. In FIG. 6, a-b-c-d and a-e-f-g are power curves of different gears, b and e are start points of the first-stage variable at different gears, and c and f are start points of the second-stage variable at different gears; the (b-c) and (e-f) are next-stage variables of different gears, and the (c-d) and (f-g) are second-stage variables of different gears.
Referring to FIGS. 3 and 4, when the negative flow valve spool 10 is not moved, P1/2 is communicated with A3, and P1/2 enters the large end of the variable piston 20; when the sum of the Pm acting force and the Ps acting force is greater than the spring force of the primary variable, when the negative flow valve core 10 moves leftwards, the A3 is disconnected from the P1/2, the A4 port is communicated with the big end of the variable piston 20, the oil is communicated with the return oil through the A4, the variable piston 20 drives the regulator 8 to move to the big end, the regulator 8 drives the shift lever 15 to rotate, the shift lever 15 drives the power valve sleeve 6 to move leftwards, the A3 is communicated with the P1/2 again, and the P1/2 oil enters the big end of the variable piston 20, which is a primary variable of power. When the sum of the Pm acting force and the Ps acting force is larger than the primary variable spring force and the secondary variable spring force, the power secondary variable is obtained.
The cross power control valve for the duplex hydraulic pump and the duplex hydraulic pump provided by the embodiment of the invention have the core innovation point that the negative flow valve core is arranged into a two-stage step structure, and P1 and P2 pressures are converted into Pm pressure through throttling confluence and then act on the negative flow valve core. Compared with a valve core with a three-level step structure in the prior art, P1 and P2 pressures need to be respectively acted on the negative flow valve core, the processing difficulty and the manufacturing cost are increased, and the clamping stagnation phenomenon is often caused by the processing precision. According to the embodiment of the invention, the annular groove is arranged between the Pm pressure and the Ps pressure of the two-stage step structure and communicated with the oil return, so that the independence of control pressure is ensured, and in the prior art, the P1 and P2, the Ps pressure oil has the risk of oil leakage to influence the control precision.
According to the cross power control valve for the duplex hydraulic pump and the duplex hydraulic pump, the negative flow valve core is designed into a two-stage step structure, and the annular groove for communicating with the return oil is arranged between the Pm action pressure and the Ps action pressure of the two-stage step structure, so that the valve core of the two-stage step structure not only greatly reduces the processing difficulty and the manufacturing cost, improves the control performance of the cross power valve, but also reduces the clamping stagnation risk caused by the processing difficulty, and avoids the influence on the control precision caused by the series flow of various pressure oils. Therefore, the technical scheme of the embodiment of the invention has good economic value and practical value and is worthy of market popularization and application.
Although the embodiments of the present invention have been described above, the above description is only for the convenience of understanding the present invention, and is not intended to limit the present invention. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (10)
1. A cross power control valve for a duplex hydraulic pump is characterized in that a valve core of the cross power control valve is of a two-stage step structure and comprises a first step part and a second step part;
the outer circle of the first step part is provided with an annular groove, the annular groove is used for communicating with an oil return port of the duplex hydraulic pump, a pilot oil pressure Ps acts on the end face of the first step part, and an outlet average oil pressure Pm of the duplex hydraulic pump acts on the step faces of the first step part and the second step part;
and the cross power control valve is used for discharging the pilot oil pressure Ps leaked to the annular groove and the outlet average oil pressure Pm through the annular groove so as to block the interference of the pilot oil pressure Ps and the outlet average oil pressure Pm.
2. The crossover power control valve for a twin hydraulic pump according to claim 1, wherein the twin hydraulic pump comprises a main pump and a slave pump, an outlet oil pressure of the main pump is P1, an outlet oil pressure of the slave pump is P2, an outlet average oil pressure Pm is an oil pressure after the outlet oil pressure P1 and the outlet oil pressure P2 are throttled and merged; pm ═ P1+ P2)/2.
3. A crossover power control valve for a tandem hydraulic pump according to claim 2, wherein said spool is a negative flow spool (10); the crossover power control valve further comprises: the variable valve comprises a valve body (13), a variable piston (20), a negative flow valve sleeve (11), a power valve core (7), a power valve sleeve (6), a positioning pin (14) and a deflector rod (15), wherein the variable piston is arranged in the valve body (13);
the negative flow valve sleeve (11) is internally provided with two-stage step holes for sleeving a negative flow valve core (10) with a two-stage step structure, and the negative flow valve sleeve (11) is internally provided with an oil return hole corresponding to the position of the annular groove for guiding oil;
the power valve core (7) is embedded into the power valve sleeve (6), one end of a deflector rod (15) is movably arranged on the power valve sleeve (6) through a positioning pin (14), so that the deflector rod can rotate along the positioning pin (14), the other end of the deflector rod (15) is connected with the top end of the regulator through a variable rod in a variable piston (20), and the deflector rod is driven by the regulator to rotate; one end face of the power valve core (7) is in contact with the end face of a second step portion in the negative flow valve core (10), a spring (9) is sleeved on the periphery of the contact portion of the power valve core (7) and the negative flow valve core (10), the spring (9) is located between the power valve sleeve (6) and the negative flow valve sleeve (11), the power valve sleeve (6) is attached to a deflector rod (15) to eliminate the invalid stroke of the power valve sleeve (6), the other end of the power valve core (7) is in contact with a spring seat (4) through a steel ball (5), and a spring assembly arranged on the spring seat (4) is used for providing pre-tightening force for the power valve core (7) and the negative flow valve core (10) to perform power adjustment on the duplex hydraulic pump; wherein, the negative flow valve core (10), the flow valve sleeve (11), the power valve core (7) and the power valve sleeve (6) are positioned on the same axis.
4. A cross power control valve for a twin hydraulic pump according to claim 3, wherein the power spool (7) and power valve housing (6) are provided with an oil return port, an oil outlet port (A3/a4), and a port Δ P communicating with the oil outlet port and communicating with the oil passage of the variable piston (20);
when the average oil pressure Pm of the outlet is smaller than the oil pressure threshold value, the oil outlets (A3/A4) of the power valve core (7) and the power valve sleeve (6) are communicated with the oil circuit of the variable piston (20) through a delta P port;
when the outlet average oil pressure Pm is increased to an oil pressure threshold value, the sum of the outlet average oil pressure Pm and the pilot oil pressure Ps is larger than the pretightening force of the spring assembly, so that the negative flow valve core (10) pushes the power valve core (7), the delta P port is closed, the oil return port is communicated with the oil path of the variable piston (20), the variable piston (20) drives the regulator to move, the driving lever (15) is driven to rotate, the power valve sleeve (6) is pushed, the power valve core and the power valve sleeve are in a dynamic balance position, and the oil outlet (A3/A4) is filled with oil.
5. A crossover power control valve for a tandem hydraulic pump according to claim 4, wherein said spring assembly comprises a primary variable spring (16) and a secondary variable spring (17), said crossover power control valve further comprising: the device comprises a first locking nut (1), a primary variable adjusting threaded sleeve (2), a secondary variable adjusting screw (3), a threaded sleeve (18) and a second locking nut (19);
one end of the secondary variable adjusting screw (3) is arranged opposite to the end face of the spring seat (4), and a secondary variable spring (17) is arranged between the secondary variable adjusting screw (3) and the spring seat (4); the one-level variable adjusting threaded sleeve (2) is sleeved at one end of the second-level variable adjusting screw (3), a one-level variable spring (16) is arranged between the one-level variable adjusting threaded sleeve (2) and the spring seat (4), the outer end of the one-level variable adjusting threaded sleeve (2) is fixed through a threaded sleeve (18) and a second locking nut (19), and the outer end of the second-level variable adjusting screw (3) is fixed through a first locking nut (1).
6. The crossover power control valve for a duplex hydraulic pump as claimed in claim 4, wherein a negative flow spring (12) is disposed between the valve body (13) and the negative flow valve sleeve (11), and a pilot oil port is disposed on the valve body (13) for providing a pilot pressure Pn to the negative flow valve sleeve (11) through the pilot oil port, so that the negative flow valve sleeve (11) pushes the negative flow spool (10) and the power spool (7) to move, thereby moving the variable piston (20) from the small end to the large section.
7. A dual hydraulic pump, comprising: a main pump, a slave pump, a pilot pump, and two variable pistons and two cross power control valves according to any one of claims 1 to 6 used in cooperation with the main pump and the slave pump, respectively;
the outlet oil pressure P1 of the main pump is connected to the small end of the corresponding variable piston and is connected to the large end of the variable piston through a cross power control valve, the outlet oil pressure P2 of the slave pump is connected to the small end of the corresponding variable piston and is connected to the large end of the variable piston through the cross power control valve, and the oil pressure Pm after the outlet oil pressure P1 of the main pump and the outlet oil pressure P2 of the slave pump are throttled and converged respectively act on the step surfaces of valve cores of the two cross power control valves;
the pilot oil pressure Ps supplied from the pilot pump acts on the end surfaces of the first step portions in the spools of the two cross power control valves, respectively.
8. The dual hydraulic pump of claim 7, wherein the spool is a negative flow spool;
the duplex hydraulic pump is used for enabling the power valve core and the power valve sleeve to be communicated with the variable piston oil path at the initial positions of the power valve core and the power valve sleeve, so that outlet oil pressure P1/P2 acts on two ends of the variable piston at the same time, the variable piston is forced to move from the large end to the small end through the area difference of the variable piston, and the main pump and the slave pump are both in the maximum displacement state.
9. The twin hydraulic pump as defined in claim 8,
the duplex hydraulic pump is also used for increasing the average oil pressure Pm at the outlet and enabling the acting force acting on the negative flow valve core to be larger than the primary spring force of the power valve, the negative flow valve core pushes the power valve core to move so that the cavity of the large end of the variable piston is communicated with the return oil, and the small end of the variable piston always acts on the outlet oil pressure P1/P2 so that the variable piston moves from the small end to the large end and the displacement of the hydraulic pump is reduced; in the process of the movement of the variable piston, a deflector rod is driven to move, and the deflector rod drives a power valve sleeve to move, so that the power valve core and the power valve sleeve are in a dynamic balance position;
the duplex hydraulic pump is also used for continuously increasing the average oil pressure Pm at the outlet and continuously pushing the power valve core to move by the negative flow valve core when the acting force acting on the negative flow valve core is larger than the sum of the primary spring force and the secondary spring force of the power valve, so that the large-end cavity of the variable piston is communicated with the return oil again.
10. The twin hydraulic pump as defined in claim 8,
the duplex hydraulic pump is also used for enabling the negative flow valve sleeve to push the negative flow valve core and the power valve core to move together through the pilot pressure Pn acting on the negative flow valve sleeve when the duplex hydraulic pump is in a standby state, the variable piston moves from the small end to the large end until the variable piston reaches the limit position, and at the moment, the hydraulic pump is in the minimum displacement state.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010728790.0A CN111980977B (en) | 2020-07-24 | 2020-07-24 | Cross power control valve for duplex hydraulic pump and duplex hydraulic pump |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010728790.0A CN111980977B (en) | 2020-07-24 | 2020-07-24 | Cross power control valve for duplex hydraulic pump and duplex hydraulic pump |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111980977A true CN111980977A (en) | 2020-11-24 |
| CN111980977B CN111980977B (en) | 2022-09-20 |
Family
ID=73438207
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010728790.0A Active CN111980977B (en) | 2020-07-24 | 2020-07-24 | Cross power control valve for duplex hydraulic pump and duplex hydraulic pump |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111980977B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114135474A (en) * | 2021-11-24 | 2022-03-04 | 力源液压（苏州）有限公司 | Total power control method and system for hydraulic plunger variable dual pump |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102704527A (en) * | 2012-06-20 | 2012-10-03 | 山河智能装备股份有限公司 | Power control device for hydraulic pump of excavator |
| CN102865207A (en) * | 2012-08-01 | 2013-01-09 | 安徽博一流体传动股份有限公司 | Axial swash plate type hydraulic plunger pump |
| CN104153419A (en) * | 2014-07-22 | 2014-11-19 | 广西柳工机械股份有限公司 | Power control valve and loader quantitative-variable hydraulic system |
| CN104358727A (en) * | 2014-10-23 | 2015-02-18 | 浙江赛克思液压有限公司 | Power control valve with negative flow control function for hydraulic pump |
| CN106593837A (en) * | 2017-02-10 | 2017-04-26 | 江苏恒立液压科技有限公司 | Variable control structure for hydraulic plunger pump and control method of variable control structure |
| CN209212681U (en) * | 2018-12-18 | 2019-08-06 | 赛克思液压科技股份有限公司 | A kind of constant-pressure control valve with pooling feature |
-
2020
- 2020-07-24 CN CN202010728790.0A patent/CN111980977B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102704527A (en) * | 2012-06-20 | 2012-10-03 | 山河智能装备股份有限公司 | Power control device for hydraulic pump of excavator |
| CN102865207A (en) * | 2012-08-01 | 2013-01-09 | 安徽博一流体传动股份有限公司 | Axial swash plate type hydraulic plunger pump |
| CN104153419A (en) * | 2014-07-22 | 2014-11-19 | 广西柳工机械股份有限公司 | Power control valve and loader quantitative-variable hydraulic system |
| CN104358727A (en) * | 2014-10-23 | 2015-02-18 | 浙江赛克思液压有限公司 | Power control valve with negative flow control function for hydraulic pump |
| CN106593837A (en) * | 2017-02-10 | 2017-04-26 | 江苏恒立液压科技有限公司 | Variable control structure for hydraulic plunger pump and control method of variable control structure |
| CN209212681U (en) * | 2018-12-18 | 2019-08-06 | 赛克思液压科技股份有限公司 | A kind of constant-pressure control valve with pooling feature |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114135474A (en) * | 2021-11-24 | 2022-03-04 | 力源液压（苏州）有限公司 | Total power control method and system for hydraulic plunger variable dual pump |
| CN114135474B (en) * | 2021-11-24 | 2024-06-18 | 苏州力源液压有限公司 | Hydraulic plunger variable duplex pump total power control method and system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111980977B (en) | 2022-09-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP2597319B1 (en) | Hydraulic oil cylinder, correlative device thereof, hydraulic cushion system, excavator and concrete pump truck | |
| CN111980977B (en) | Cross power control valve for duplex hydraulic pump and duplex hydraulic pump | |
| US6068013A (en) | Counter balance valve | |
| CN108412831B (en) | Shunt pressure-regulating speed-regulating reversing integrated valve | |
| CN112576781A (en) | Proportional valve with pressure reducing and reversing functions | |
| CN109058208B (en) | Buffer overflow valve | |
| CN113464394B (en) | Torque control device for plunger pump | |
| CN215830837U (en) | Compact structure type load sensitive valve | |
| JP2000227102A (en) | Relief valve | |
| CN214424647U (en) | Electric proportional plunger pump and variable control device thereof | |
| CN103912534A (en) | Constant-difference overflow valve with unloading function | |
| CN114165402A (en) | Constant power control device and method for plunger pump | |
| CN113898628A (en) | Super-large flow bidirectional balance valve | |
| CN112377381A (en) | Electric proportional plunger pump and variable control device thereof | |
| CN109026888B (en) | Rotary buffer valve | |
| CN216382016U (en) | Adjusting mechanism for hydraulic motor automatic variable valve based on load feedback | |
| CN113623284B (en) | Compact structure type load sensitive valve | |
| CN212028216U (en) | Hydraulic control valve and variable displacement hydraulic pump with same | |
| CN216812341U (en) | Three-way pressure control valve with valve core provided with pre-boosting groove | |
| CN219774877U (en) | Two-point hydraulic control valve with pressure cut-off for motor | |
| CN219865680U (en) | Internal throttling bidirectional hydraulic lock | |
| CN219299660U (en) | Slide valve type high-pressure overflow unidirectional integrated valve | |
| CN215804761U (en) | Pilot valve and two-stage variable displacement engine oil pump control system thereof | |
| CN217354981U (en) | Valve bush valve core assembly, power valve, hydraulic power mechanism and engineering machinery | |
| CN216077784U (en) | Unloading valve and combined valve type buffer oil cylinder |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |