CN111720376A - Flow dividing valve, hydraulic system thereof and engineering machinery - Google Patents
Flow dividing valve, hydraulic system thereof and engineering machinery Download PDFInfo
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- CN111720376A CN111720376A CN202010604721.9A CN202010604721A CN111720376A CN 111720376 A CN111720376 A CN 111720376A CN 202010604721 A CN202010604721 A CN 202010604721A CN 111720376 A CN111720376 A CN 111720376A
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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
- F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
- F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
- F15B11/17—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors using two or more pumps
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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
- F15B13/022—Flow-dividers; Priority valves
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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
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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
- F15B21/00—Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
- F15B21/04—Special measures taken in connection with the properties of the fluid
- F15B21/041—Removal or measurement of solid or liquid contamination, e.g. filtering
Abstract
The invention discloses a flow dividing valve, a hydraulic system thereof and engineering machinery, wherein the flow dividing valve comprises a throttling valve, a first hydraulic control valve, a second hydraulic control valve, a one-way valve, a sequence valve, a third hydraulic control valve and a shuttle valve, an oil inlet of the flow dividing valve is communicated with a flow merging port through the throttling valve and the one-way valve in sequence, and the front pressure and the rear pressure of the throttling valve are respectively communicated with a control cavity at each end of the second hydraulic control valve; the outlet end of the throttle valve is respectively connected with the oil return port T2 through a first hydraulic control valve and a third hydraulic control valve which are positioned at a working position, and is used for unloading through the first hydraulic control valve and the third hydraulic control valve; the first hydraulic control valve control cavity is communicated with the oil return port T3 through a second hydraulic control valve in a first working position; control port c1 and control port c2 are each connected to an inlet of the shuttle valve; the working port of the shuttle valve is communicated with the control cavity of the first hydraulic control valve through a second hydraulic control valve at a second working position; the confluence port P2 is connected to the control end of the third pilot controlled valve through a sequence valve. The flow of the confluence oil inlet and the unloading oil inlet or the pressure of the confluence opening is realized.
Description
Technical Field
The invention belongs to the technical field of engineering machinery, and particularly relates to a flow dividing valve, a hydraulic system of the flow dividing valve and the engineering machinery.
Background
At present, a power source part of a hydraulic system adopts an internal combustion engine, if a fixed displacement pump is adopted as a power element, the flow of the system changes along with the change of the rotating speed of the internal combustion engine, which has great influence on the performance of the hydraulic system, and particularly when the rotating speed of the internal combustion engine is low, the efficiency of the hydraulic system is obviously reduced. If the displacement of the fixed displacement pump is increased to ensure that the system flow is sufficient when the internal combustion engine rotates at a low speed, the fixed displacement pump can provide a large amount of redundant flow or throttle or overflow when the internal combustion engine rotates at a high speed, which causes energy waste, and meanwhile, when the pressure of the system is high, the required torque of the fixed displacement pump is increased to influence the output of a power source. Generally, a hydraulic system has more than one actuator, the demand flow of the actuators is different, and the design is based on the actuator with the maximum flow, so that the flow of the actuator with low demand flow is wasted, and the flow exceeding the demand flow is possibly harmful. In order to solve the contradiction, the technical scheme adopted in the market at present adopts a variable pump to provide corresponding flow according to the requirement of an actuating element, but the variable pump has higher cost and complex system.
Disclosure of Invention
The purpose is as follows: in order to overcome the defects in the prior art, the invention provides a flow dividing valve, a hydraulic system of the flow dividing valve and engineering machinery of the flow dividing valve. According to the change of the pump flow of the hydraulic system, the flow converging to the system is automatically adjusted, the flow of different execution elements of the system is ensured, the energy waste is avoided, the harm caused by overlarge flow is eliminated, and meanwhile, the flow of the system is adjusted according to the system pressure, so that the overlarge torque required by the first pump and the second pump is avoided, and the influence on the output of a power source is avoided.
The technical scheme is as follows: in order to solve the technical problems, the technical scheme adopted by the invention is as follows:
in a first aspect, a flow dividing valve is provided, which comprises a throttle valve, a first hydraulic control valve, a second hydraulic control valve, a one-way valve, a sequence valve, a third hydraulic control valve and a shuttle valve, wherein the flow dividing valve is provided with a control port c1, a control port c2, a flow merging port P2, an oil inlet P3, an oil return port T2 and an oil return port T3;
an oil inlet P3 of the flow divider is communicated with a flow merging port P2 through a throttle valve and a one-way valve in sequence, the front pressure of the throttle valve is communicated with a control cavity at one end of a second hydraulic control valve, the rear pressure of the throttle valve is communicated with a control cavity at the other end of the second hydraulic control valve and is used for controlling the position of a valve core of the second hydraulic control valve;
the outlet end of the throttle valve is respectively connected with an oil return port T2 through a first hydraulic control valve in one working position and a third hydraulic control valve in one working position, and is used for unloading through the first hydraulic control valve and the third hydraulic control valve; the first hydraulic control valve control cavity is communicated with the oil return port T3 through a second hydraulic control valve in a first working position;
one of the control port c1 and the control port c2 is connected to one inlet of the shuttle valve, and the other of the control port c1 and the control port c2 is connected to the other inlet of the shuttle valve; the working port of the shuttle valve is communicated with the control cavity of the first hydraulic control valve through a second hydraulic control valve at a second working position and is used for controlling the position of the valve core of the first hydraulic control valve;
one end of the sequence valve is connected with the confluence port P2, and the other end of the sequence valve is connected with the control end of the third hydraulic control valve for controlling the position of the valve core of the third hydraulic control valve.
In some embodiments, the control port c1 of the flow divider valve is connected to the lower inlet of the shuttle valve, the control port c2 is connected to the upper inlet of the shuttle valve, and the outlet end of the throttle valve is connected with the oil return port T2 through the first hydraulic control valve at the right position and the third hydraulic control valve at the right position respectively;
when the flow of the oil inlet P3 does not exceed a set value, the first hydraulic control valve control cavity is communicated with the oil return port T3 through the second hydraulic control valve which is at the upper position, the first hydraulic control valve is at the right position under the force of the return spring, the flow of the oil inlet P3 cannot be unloaded through the first hydraulic control valve in the flow dividing valve, and the flow of the oil inlet P3 flows to the confluence port P2 to be converged;
when the flow of the oil inlet P3 exceeds a set value, a working port of the shuttle valve is communicated with a control port of a first hydraulic control valve through a second hydraulic control valve at a lower position, the first hydraulic control valve moves left, and the flow of the oil inlet P3 is unloaded through the first hydraulic control valve in the flow dividing valve;
when the pressure of the confluence port P2 exceeds a preset value, the sequence valve is opened to push the third hydraulic control valve to be reversed to the left position, the flow of the confluence port P2 is unloaded back to the hydraulic oil tank through the third hydraulic control valve, and the pressure of the confluence port P2 is unloaded.
In a second aspect, a hydraulic system is provided, which comprises a hydraulic oil tank, a first pump, a second pump, a pilot valve, a multi-way valve, a first actuator, a second actuator and a flow dividing valve as claimed in claim 1 or 2; the first pump and the second pump are both fixed displacement pumps;
the first pump comprises a front pump and a rear pump; the oil inlets of the front pump, the rear pump and the second pump are all connected with a hydraulic oil tank, the oil outlet of the front pump is connected with an oil inlet P1 of the multi-way valve and a confluence port P2 of the diverter valve, the oil outlet of the second pump is connected with an oil inlet P3 of the diverter valve, and the oil outlet of the rear pump is connected with an oil inlet P4 of the pilot valve; the control port a1 of the pilot valve is connected with the control port b1 of the multi-way valve and the control port c1 of the shunt valve, the control port a2 of the pilot valve is connected with the control port b2 of the multi-way valve and the control port c2 of the shunt valve, the control port a3 of the pilot valve is connected with the control port b3 of the multi-way valve, and the control port a4 of the pilot valve is connected with the control port b4 of the multi-way;
a working oil port A1 of the multi-way valve is connected with an oil port of a rodless cavity of the first actuating element, a working oil port B1 of the multi-way valve is connected with an oil port of a rod cavity of the first actuating element, a working oil port A2 of the multi-way valve is connected with a rodless cavity of the second actuating element, and a working oil port B2 of the multi-way valve is connected with an oil port of a rod cavity of the second actuating element;
the oil return port T1 of the multi-way valve and the oil return ports T2 and T3 of the flow dividing valve are connected with a hydraulic oil tank.
In some embodiments, the first actuator is a hydraulic ram.
In some embodiments, the second actuator is a hydraulic ram.
In some embodiments, the multiplex valve is a pilot controlled multiplex valve.
In some embodiments, an overflow valve is further arranged at the oil outlet of the rear pump, and the overflow valve flows back to the hydraulic oil tank through the overflow port.
In a third aspect, the invention further provides a construction machine, which comprises the hydraulic system.
Has the advantages that: according to the flow divider valve, the hydraulic system and the engineering machinery provided by the invention, the second pump is added, the flow of the flow dividing valve is automatically adjusted according to the flow change of the second pump and the action of the operation element, so that the requirement of high flow rate of the first double-pump flow dividing of the operation element is ensured, the stability of two-phase flow dividing of the operation element is ensured, the first pump supplies oil when the two flow rates of the pump are high, the second pump unloads, and the double pumps merge when the two flow rates of the pump are insufficient, thereby reducing energy waste and avoiding the harm caused by the high flow rate. When the system pressure exceeds a certain value, the two-way pump is unloaded through the throttling valve, so that the torque required by the first pump and the second pump is controlled within a certain range, and the output of a power source is not influenced.
Drawings
FIG. 1 is a schematic diagram of a diverter valve according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a hydraulic system according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of a first pump in an embodiment;
in the figure: the hydraulic control system comprises a hydraulic oil tank 1, a first pump 2, a second pump 3, a pilot valve 4, a multi-way valve 5, a flow dividing valve 6, a first actuating element 7 and a second actuating element 8; a front pump 21, a rear pump 22, and an overflow valve 23; a throttle valve 61, a first pilot operated valve 62, a second pilot operated valve 63, a check valve 64, a sequence valve 65, a third pilot operated valve 66, a shuttle valve 67.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.
Example 1
As shown in fig. 1, a flow dividing valve includes a throttle valve 61, a first pilot-controlled valve 62, a second pilot-controlled valve 63, a check valve 64, a sequence valve 65, a third pilot-controlled valve 66, and a shuttle valve 67, and the flow dividing valve is provided with a control port c1, a control port c2, a flow merging port P2, an oil inlet P3, an oil return port T2, and an oil return port T3;
an oil inlet P3 of the flow divider 6 is communicated with a confluence port P2 through a throttle valve 61 and a check valve 64 in sequence, the front pressure of the throttle valve 61 is communicated with a control cavity at one end of a second hydraulic control valve 63, the rear pressure of the throttle valve 61 is communicated with a control cavity at the other end of the second hydraulic control valve 63, and the control cavity is used for controlling the valve core position of the second hydraulic control valve 63;
the outlet end of the throttle valve 61 is connected with an oil return port T2 through a first hydraulic control valve 62 in one working position and a third hydraulic control valve 66 in one working position respectively, and is used for unloading through the first hydraulic control valve 62 and the third hydraulic control valve 66; the control cavity of the first hydraulic control valve 62 is communicated with the oil return port T3 through the second hydraulic control valve 63 in the first working position;
one of the control ports c1 and c2 is connected to one inlet of the shuttle valve 67, and the other of the control ports c1 and c2 is connected to the other inlet of the shuttle valve 67; the working port of the shuttle valve 67 is communicated with the control cavity of the first hydraulic control valve 62 through the second hydraulic control valve 63 at the second working position and is used for controlling the valve core position of the first hydraulic control valve 62;
the sequence valve 65 has one end connected to the merging port P2 and the other end connected to the pilot port of the third pilot-controlled valve 66 for controlling the spool position of the third pilot-controlled valve 66.
In some embodiments, as shown in fig. 1, the pilot port c1 of the flow divider valve 6 is connected to the lower inlet of the shuttle valve 67, the pilot port c2 is connected to the upper inlet of the shuttle valve 67, and the outlet of the throttle valve 61 is connected to the return port T2 through the first pilot-controlled valve 62 in the right position and the third pilot-controlled valve 66 in the right position, respectively;
when the flow of the oil inlet P3 does not exceed a set value, the control cavity of the first hydraulic control valve 62 is communicated with the oil return port T3 through the second hydraulic control valve 63 which is at the upper position, the first hydraulic control valve 62 is at the right position under the force of the return spring, the flow of the oil inlet P3 cannot be unloaded through the first hydraulic control valve 62 in the flow dividing valve 6, and the flow of the oil inlet P3 flows to the confluence port P2 to be converged;
when the flow of the oil inlet P3 exceeds a set value, the working port of the shuttle valve 67 is communicated with the control port of the first hydraulic control valve 62 through the second hydraulic control valve 63 at the lower position, the first hydraulic control valve 62 moves to the left, and the flow of the oil inlet P3 is unloaded through the first hydraulic control valve 62 in the flow dividing valve 6;
when the pressure of the confluence port P2 exceeds a preset value, the sequence valve 65 is opened to push the third hydraulic control valve 66 to be switched to the left position, the flow of the confluence port P2 is unloaded back to the hydraulic oil tank 1 through the third hydraulic control valve 66, and the pressure of the confluence port P2 is unloaded.
Example 2
As shown in fig. 2, a hydraulic system includes a hydraulic oil tank 1, a first pump 2, a second pump 3, a pilot valve 4, a multi-way valve 5, a first actuator 7, a second actuator 8, and the above-mentioned flow dividing valve 6; the first pump 2 and the second pump 3 are fixed displacement pumps;
as shown in fig. 3, the first pump 2 comprises a front pump 21, a rear pump 22 and an overflow valve 23; the oil inlets of the front pump 21, the rear pump 22 and the second pump 3 are all connected with the hydraulic oil tank 1, the oil outlet of the front pump 21 is connected with the oil inlet P1 of the multi-way valve 5 and the confluence port P2 of the diverter valve 6, the oil outlet of the second pump 3 is connected with the oil inlet P3 of the diverter valve 6, and the oil outlet of the rear pump 22 is connected with the oil inlet P4 of the pilot valve 4; the control port a1 of the pilot valve 4 is connected with the control port b1 of the multi-way valve 5 and the control port c1 of the flow dividing valve 6, the control port a2 of the pilot valve 4 is connected with the control port b2 of the multi-way valve 5 and the control port c2 of the flow dividing valve 6, the control port a3 of the pilot valve 4 is connected with the control port b3 of the multi-way valve 5, and the control port a4 of the pilot valve 4 is connected with the control port b4 of the multi-way valve 5;
a working oil port A1 of the multi-way valve 5 is connected with an oil port of a rodless cavity of the first actuating element 7, a working oil port B1 of the multi-way valve 5 is connected with an oil port of a rod cavity of the first actuating element 7, a working oil port A2 of the multi-way valve 5 is connected with a rodless cavity of the second actuating element 8, and a working oil port B2 of the multi-way valve 5 is connected with an oil port of a rod cavity of the second actuating element 8;
the return port T1 of the multiplex valve 5 and the return ports T2 and T3 of the flow dividing valve 6 are connected to the hydraulic oil tank 1.
In some embodiments, the first and second actuators include, but are not limited to, hydraulic rams.
In some embodiments, the multiplex valve 5 is a pilot controlled multiplex valve.
In some embodiments, as shown in fig. 3, a relief valve 23 is further provided at the oil outlet of the rear pump 22, and flows back to the hydraulic oil tank 1 through the relief port.
The flow of the second pump 3 passes through the flow divider 6, and the flow of the flow divider 6 merged into the system is controlled according to different flow of the second pump 3 and different operation requirements.
On the basis of the structure, the oil inlets of the first pump 2 and the second pump 3 can be respectively connected with the hydraulic oil tank 1, or the oil inlets of the two pumps can be connected with the hydraulic oil tank 1 after being connected. The first pump 2 and the second pump 3 can be directly connected with the hydraulic oil tank 1, and can also be connected with the hydraulic oil tank 1 through the filter element to filter impurities in hydraulic oil.
The working process of the invention is as follows: when the system does not operate, the control ports of the pilot valve 4, the multi-way valve 5 and the flow divider 6 have no pressure, the valve core of the multi-way valve 5 is positioned at the middle position, the flow of the pump I2 flows in through the oil port P1 of the multi-way valve 5, and directly returns to the oil tank from the oil return port T1 of the multi-way valve 5; the flow of the second pump 3 flows from the flow divider valve 6 port P3 through the internal check valve 64, then flows through the multiplex valve 5 port P1, and also returns to the tank directly from the multiplex valve 5 return port T1.
When the system operates the second actuator 8 to extend, the pilot valve 4 communicates with the oil inlet P4 and the control port a2, the oil at the outlet of the rear pump 22 in the first pump 2 enters the control port b2 of the multi-way valve 5 through the pilot valve 4, the control valve core of the second actuator 8 in the multi-way valve 5 moves to the left, the surplus oil at the outlet of the rear pump 22 overflows from the overflow valve 23 back to the hydraulic oil tank 1, the oil at the outlet of the second pump 3 passes through the flow dividing valve 6, and enters the rodless cavity of the second actuator 8 through the multi-way valve 5 after being converged with the front pump 21 of the first pump 2, and the. When the second actuator 8 is operated to extend, the pressure of the control port a2 of the pilot valve 4 is simultaneously transmitted to the control port c2 of the flow divider 6, the upper position of the shuttle valve 67 in the flow divider 6 is opened, the lower position of the shuttle valve is closed, the pressure of the control port c2 enters the oil inlet of the second hydraulic valve 63, the oil at the outlet of the second pump 3 generates pressure loss when passing through the throttle valve 61 in the flow divider 6, the pressure loss is proportional to the flow of the second pump 3, the pressure in front of the throttle valve 61 is communicated with the control cavity at the lower end of the second hydraulic valve 63, and the pressure in the rear of the throttle valve 61 is communicated with. When the flow of the second pump 3 is small, the pressure difference between the two ends of the throttle valve 61 is not enough to overcome the return spring force of the second hydraulic control valve 63, the second hydraulic control valve 63 works in an upper position, the control cavity of the first hydraulic control valve 62 is communicated with the hydraulic oil tank 1 through the second hydraulic control valve 63, the first hydraulic control valve 62 is in a right position under the return spring force, the second pump 3 cannot be unloaded through the first hydraulic control valve 62 in the flow dividing valve 6, double-pump confluence is realized, and a large flow is supplied to the second execution element 8. When the flow of the second pump 3 exceeds a certain value, the pressure at the two ends of the throttle valve 61 is enough to overcome the return spring force of the second hydraulic control valve 63, the second hydraulic control valve 63 works at the lower position, the pressure of the control port c2 of the flow dividing valve is communicated with the control port of the first hydraulic control valve 62 through the second hydraulic control valve 63, the first hydraulic control valve 62 moves leftwards, and the second pump 3 is unloaded through the first hydraulic control valve 62 in the flow dividing valve 6, so that the second pump 3 is unloaded. When the system pressure is higher than a certain value along with the load change of the second execution element 8, the sequence valve 65 in the flow dividing valve 6 is opened to push the third hydraulic control valve 66 to be reversed to the left position, and the second pump 3 is unloaded back to the hydraulic oil tank 1 through the third hydraulic control valve 66, so that the required torques of the second pump 3, the first control pump 2 and the second control pump 3 are controlled below a certain value when the system pressure is high.
When the system operates the second actuator 8 to retract, the pilot valve 4 communicates with the oil inlet P4 and the control port a1, oil at the outlet of the rear pump 22 in the first pump 2 enters the control port b1 of the multi-way valve 5 through the pilot valve 4, the control valve core of the second actuator 8 in the multi-way valve 5 moves to the right, redundant oil at the outlet of the rear pump 22 overflows from the overflow valve 23 to the hydraulic oil tank 1, oil at the outlet of the second pump 3 passes through the flow dividing valve 6, is converged with the first pump 2 and then enters the rod cavity of the second actuator 8 through the multi-way valve 5, and the second actuator 8 retracts. When the second actuator 8 is operated to retract, the pressure of the control port a1 of the pilot valve 4 is transmitted to the control port c1 of the flow dividing valve 6, the lower position of the shuttle valve 67 in the flow dividing valve 6 is opened, the upper position of the shuttle valve is closed, the pressure of the control port c1 enters the oil inlet of the second hydraulic valve 63, pressure loss is generated when oil at the outlet of the second pump 3 flows through the throttle valve 61 in the flow dividing valve 6, the pressure loss is in direct proportion to the flow of the second pump 3, the pressure in front of the throttle valve 61 is communicated with the control cavity at the lower end of the second hydraulic valve 63, and the pressure in the rear of. When the flow of the second pump 3 is small, the pressure difference between the two ends of the throttle valve 61 is not enough to overcome the return spring force of the second hydraulic control valve 63, the second hydraulic control valve 63 works in an upper position, the control cavity of the first hydraulic control valve 62 is communicated with the hydraulic oil tank 1 through the second hydraulic control valve 63, the first hydraulic control valve 62 is in a right position under the return spring force, the second pump 3 cannot be unloaded through the first hydraulic control valve 62 in the flow dividing valve 6, double-pump confluence is realized, and a large flow is supplied to the second execution element 8. When the flow of the second pump 3 exceeds a certain value, the pressure at the two ends of the throttle valve 61 is enough to overcome the return spring force of the second hydraulic control valve 63, the second hydraulic control valve 63 works at the lower position, the pressure of the control port c1 of the flow dividing valve is communicated with the control port of the first hydraulic control valve 62 through the second hydraulic control valve 63, the first hydraulic control valve 62 moves leftwards, and the second pump 3 is unloaded through the first hydraulic control valve 62 in the flow dividing valve 6, so that the second pump 3 is unloaded. When the system pressure is higher than a certain value along with the load change of the second execution element 8, the sequence valve 65 in the flow dividing valve 6 is opened to push the third hydraulic control valve 66 to be reversed to the left position, and the second pump 3 is unloaded back to the hydraulic oil tank 1 through the third hydraulic control valve 66, so that the required torques of the second pump 3, the first control pump 2 and the second control pump 3 are controlled below a certain value when the system pressure is high.
When the system operates the first actuator 7 to extend, the pilot valve 4 communicates with the oil inlet P4 and the control port a4, oil at the outlet of the rear pump 22 in the first pump 2 enters the control port b4 of the multi-way valve 5 through the pilot valve 4, the control valve core of the first actuator 7 in the multi-way valve 5 moves to the left, redundant oil at the outlet of the rear pump 22 overflows from the overflow valve 23 back to the hydraulic oil tank 1, oil at the outlet of the second pump 3 passes through the flow dividing valve 6, is converged with the first pump 2 and then enters the rodless cavity of the first actuator 7 through the multi-way valve 5, and the first actuator 7 extends. When the first actuator 7 is operated to extend, the control ports a1 and a2 of the pilot valve 4 are not pressurized, so the control ports c1 and c2 of the flow dividing valve 6 are also not pressurized, no matter how much the flow of the second pump 3 is, the position of the second hydraulic control valve 63 in the flow dividing valve 6 is caused, the first hydraulic control valve 62 is always in the right position, the second pump 3 cannot be unloaded through the first hydraulic control valve 62 in the flow dividing valve 6, double-pump confluence is realized, and large flow is supplied to the first actuator 7. When the system pressure is higher than a certain value along with the load change of the first actuator 7, the sequence valve 65 in the flow dividing valve 6 is opened to push the third hydraulic control valve 66 to be reversed to the left position, and the second pump 3 is unloaded back to the hydraulic oil tank 1 through the third hydraulic control valve 66, so that the required torques of the second pump 3, the first control pump 2 and the second control pump 3 are controlled below a certain value when the system pressure is high.
When the system operates the first actuator 7 to retract, the pilot valve 4 communicates with the oil inlet P4 and the control port a3, oil at the outlet of the rear pump 22 in the first pump 2 enters the control port b3 of the multi-way valve 5 through the pilot valve 4, the control valve core of the first actuator 7 in the multi-way valve 5 moves to the right, redundant oil at the outlet of the rear pump 22 overflows from the overflow valve 23 back to the hydraulic oil tank 1, oil at the outlet of the second pump 3 passes through the flow dividing valve 6, is converged with the first pump 2 and then enters the rod cavity of the first actuator 7 through the multi-way valve 5, and the first actuator 7. When the first actuator 7 is operated to retract, the control ports a1 and a2 of the pilot valve 4 are not pressurized, so the control ports c1 and c2 of the flow dividing valve 6 are also not pressurized, no matter what the flow of the second pump 3 is, the position of the second hydraulic control valve 63 in the flow dividing valve 6 is caused, the first hydraulic control valve 62 is always in the right position, the second pump 3 cannot be unloaded through the first hydraulic control valve 62 in the flow dividing valve 6, double-pump confluence is realized, and a large flow is supplied to the first actuator 7. When the system pressure is higher than a certain value along with the load change of the first actuator 7, the sequence valve 65 in the flow dividing valve 6 is opened to push the third hydraulic control valve 66 to be reversed to the left position, and the second pump 3 is unloaded back to the hydraulic oil tank 1 through the third hydraulic control valve 66, so that the required torques of the second pump 3, the first control pump 2 and the second control pump 3 are controlled below a certain value when the system pressure is high.
In the working process of the system, when the system pressure is higher than the set value of the safety valve of the multi-way valve 5, the safety valve of the multi-way valve 5 is opened, and the flow of the pump I2 is unloaded through the safety valve of the multi-way valve 5.
Example 3
In another aspect, a working machine is also provided, which comprises the hydraulic system.
In the description of the present invention, it is to be understood that the terms "central", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be considered as limiting the scope of the present invention.
The above description is only of the preferred embodiments of the present invention, and it should be noted that: it will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the principles of the invention and these are intended to be within the scope of the invention.
Claims (8)
1. A flow dividing valve is characterized by comprising a throttling valve, a first hydraulic control valve, a second hydraulic control valve, a one-way valve, a sequence valve, a third hydraulic control valve and a shuttle valve, wherein the flow dividing valve is provided with a control port c1, a control port c2, a flow merging port P2, an oil inlet P3, an oil return port T2 and an oil return port T3;
an oil inlet P3 of the flow divider is communicated with a flow merging port P2 through a throttle valve and a one-way valve in sequence, the front pressure of the throttle valve is communicated with a control cavity at one end of a second hydraulic control valve, the rear pressure of the throttle valve is communicated with a control cavity at the other end of the second hydraulic control valve and is used for controlling the position of a valve core of the second hydraulic control valve;
the outlet end of the throttle valve is respectively connected with an oil return port T2 through a first hydraulic control valve in one working position and a third hydraulic control valve in one working position, and is used for unloading through the first hydraulic control valve and the third hydraulic control valve; the first hydraulic control valve control cavity is communicated with the oil return port T3 through a second hydraulic control valve in a first working position;
one of the control port c1 and the control port c2 is connected to one inlet of the shuttle valve, and the other of the control port c1 and the control port c2 is connected to the other inlet of the shuttle valve; the working port of the shuttle valve is communicated with the control cavity of the first hydraulic control valve through a second hydraulic control valve at a second working position and is used for controlling the position of the valve core of the first hydraulic control valve;
one end of the sequence valve is connected with the confluence port P2, and the other end of the sequence valve is connected with the control end of the third hydraulic control valve for controlling the position of the valve core of the third hydraulic control valve.
2. The flow divider valve of claim 1 wherein control port c1 is connected to the lower inlet port of the shuttle valve, control port c2 is connected to the upper inlet port of the shuttle valve, and the throttle valve outlet port is connected to the return port T2 via a first pilot operated valve at right position and a third pilot operated valve at right position, respectively;
when the flow of the oil inlet P3 does not exceed a set value, the first hydraulic control valve control cavity is communicated with the oil return port T3 through the second hydraulic control valve which is at the upper position, the first hydraulic control valve is at the right position under the force of the return spring, the flow of the oil inlet P3 cannot be unloaded through the first hydraulic control valve in the flow dividing valve, and the flow of the oil inlet P3 flows to the confluence port P2 to be converged;
when the flow of the oil inlet P3 exceeds a set value, a working port of the shuttle valve is communicated with a control port of a first hydraulic control valve through a second hydraulic control valve at a lower position, the first hydraulic control valve moves left, and the flow of the oil inlet P3 is unloaded through the first hydraulic control valve in the flow dividing valve;
when the pressure of the confluence port P2 exceeds a preset value, the sequence valve is opened to push the third hydraulic control valve to be reversed to the left position, the flow of the confluence port P2 is unloaded back to the hydraulic oil tank through the third hydraulic control valve, and the pressure of the confluence port P2 is unloaded.
3. A hydraulic system comprising a hydraulic tank, a first pump, a second pump, a pilot valve, a multi-way valve, a first actuator, a second actuator and a flow divider valve according to claim 1 or 2; the first pump and the second pump are both fixed displacement pumps;
the first pump comprises a front pump and a rear pump; the oil inlets of the front pump, the rear pump and the second pump are all connected with a hydraulic oil tank, the oil outlet of the front pump is connected with an oil inlet P1 of the multi-way valve and a confluence port P2 of the diverter valve, the oil outlet of the second pump is connected with an oil inlet P3 of the diverter valve, and the oil outlet of the rear pump is connected with an oil inlet P4 of the pilot valve; the control port a1 of the pilot valve is connected with the control port b1 of the multi-way valve and the control port c1 of the shunt valve, the control port a2 of the pilot valve is connected with the control port b2 of the multi-way valve and the control port c2 of the shunt valve, the control port a3 of the pilot valve is connected with the control port b3 of the multi-way valve, and the control port a4 of the pilot valve is connected with the control port b4 of the multi-way;
a working oil port A1 of the multi-way valve is connected with an oil port of a rodless cavity of the first actuating element, a working oil port B1 of the multi-way valve is connected with an oil port of a rod cavity of the first actuating element, a working oil port A2 of the multi-way valve is connected with a rodless cavity of the second actuating element, and a working oil port B2 of the multi-way valve is connected with an oil port of a rod cavity of the second actuating element;
the oil return port T1 of the multi-way valve and the oil return ports T2 and T3 of the flow dividing valve are connected with a hydraulic oil tank.
4. The hydraulic system of claim 3, wherein the first actuator is a hydraulic ram.
5. The hydraulic system of claim 3, wherein the second actuator is a hydraulic ram.
6. The hydraulic system of claim 3, wherein the multiplex valve is a pilot controlled multiplex valve.
7. The hydraulic system as claimed in claim 3, characterized in that an overflow valve is further provided at the oil outlet of the rear pump, and flows back to the hydraulic oil tank through an overflow port.
8. A working machine, characterized in that it comprises a hydraulic system according to any one of claims 3-7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010604721.9A CN111720376A (en) | 2020-06-29 | 2020-06-29 | Flow dividing valve, hydraulic system thereof and engineering machinery |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010604721.9A CN111720376A (en) | 2020-06-29 | 2020-06-29 | Flow dividing valve, hydraulic system thereof and engineering machinery |
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| Publication Number | Publication Date |
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| CN111720376A true CN111720376A (en) | 2020-09-29 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202010604721.9A Pending CN111720376A (en) | 2020-06-29 | 2020-06-29 | Flow dividing valve, hydraulic system thereof and engineering machinery |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113090599A (en) * | 2021-03-31 | 2021-07-09 | 徐工集团工程机械股份有限公司科技分公司 | Logic control valve and hydraulic system |
-
2020
- 2020-06-29 CN CN202010604721.9A patent/CN111720376A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113090599A (en) * | 2021-03-31 | 2021-07-09 | 徐工集团工程机械股份有限公司科技分公司 | Logic control valve and hydraulic system |
| CN113090599B (en) * | 2021-03-31 | 2022-07-05 | 徐工集团工程机械股份有限公司科技分公司 | Logic control valve and hydraulic system |
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