CN115573955A - Heavy load control hydraulic system and engineering machinery - Google Patents
Heavy load control hydraulic system and engineering machinery Download PDFInfo
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- CN115573955A CN115573955A CN202211181803.2A CN202211181803A CN115573955A CN 115573955 A CN115573955 A CN 115573955A CN 202211181803 A CN202211181803 A CN 202211181803A CN 115573955 A CN115573955 A CN 115573955A
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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
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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
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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
- F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
- F15B15/20—Other details, e.g. assembly with regulating devices
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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
- F15B21/02—Servomotor systems with programme control derived from a store or timing device; Control devices therefor
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- Analytical Chemistry (AREA)
- Fluid-Pressure Circuits (AREA)
Abstract
The invention discloses an engineering machine and a heavy load control hydraulic system, wherein the heavy load control hydraulic system comprises: a hydraulic pump; the hydraulic executive part comprises a first working oil port, a second working oil port and an action part connected with the heavy load; a reversing valve; the load control valve comprises a first oil port, a second oil port, an elastic control end and a first hydraulic control end, wherein the valve core of the load control valve tends to move towards the direction of closing a communication channel of the first oil port and the second oil port due to the elastic force of the elastic control end, the valve core of the load control valve tends to move towards the direction of opening the communication channel of the first oil port and the second oil port due to pressure oil introduced into the first hydraulic control end of the load control valve, the first oil port is connected with a second working oil port, the first hydraulic control end of the load control valve comprises a first control port connected with the first working oil port, and the second oil port is connected with a reversing oil inlet; and the oil inlet of the first check valve is connected with the second reversing working oil port, and the oil outlet of the first check valve is connected with the pipeline between the second reversing working oil ports.
Description
Technical Field
The invention relates to the technical field of engineering machinery hydraulic pressure, in particular to a heavy load control hydraulic system and engineering machinery.
Background
In a construction machine, there are often some heavy loads (loads with heavy weight) for performing an elevating operation, and the elevating operation of the heavy loads is generally controlled by directly or indirectly connecting with a hydraulic actuator such as a hydraulic cylinder or a hydraulic motor. Heavy load is heavy, gravity is heavy, and whether the descending process is stable and controllable is a problem which needs to be considered frequently in the field of engineering machinery.
Disclosure of Invention
The invention aims to provide a heavy load control hydraulic system which can smoothly control the lifting of a heavy load and can save energy and an engineering machine using the heavy load control hydraulic system.
The invention discloses a first aspect discloses a heavy load control hydraulic system, comprising:
a hydraulic pump for providing pressure oil;
at least one execution device comprising:
the hydraulic actuator comprises a first working oil port, a second working oil port and a working piece connected with a heavy load, wherein when the working piece acts in a first direction, the heavy load descends, when the working piece acts in a second direction opposite to the first direction, the heavy load ascends, pressure oil introduced from the first working oil port provides pressure enabling the working piece to tend to act in the first direction, and pressure oil introduced from the second working oil port provides pressure enabling the working piece to tend to act in the second direction;
the reversing valve comprises a first reversing working oil port connected with the first working oil port, a second reversing working oil port connected with the second working oil port, a reversing oil inlet connected with the hydraulic pump and a reversing oil outlet connected with an oil tank, and has a first reversing state and a second reversing state, wherein in the first reversing state, the first reversing working oil port is communicated with the reversing oil outlet, the second reversing working oil port is communicated with the reversing oil inlet, in the second reversing state, the first reversing working oil port is communicated with the reversing oil inlet, and the second reversing working oil port is communicated with the reversing oil outlet;
the load control valve comprises a first oil port, a second oil port, an elastic control end and a first hydraulic control end, wherein the first hydraulic control end is positioned on the opposite side of the elastic control end, the elastic force of the elastic control end enables a valve core of the load control valve to tend to move towards the direction of closing a communication channel of the first oil port and the second oil port, pressure oil introduced into the first hydraulic control end of the load control valve enables the valve core of the load control valve to tend to move towards the direction of opening the communication channel of the first oil port and the second oil port, the first oil port is connected with the second working oil port, the first hydraulic control end of the load control valve comprises a first control port connected with the first oil port, and the second oil port is connected with the reversing oil inlet;
an oil inlet of the first check valve is connected with the second reversing working oil port, and an oil outlet of the first check valve is connected with a pipeline between the first oil port and the second working oil port.
In some embodiments, the actuating device further includes a second check valve connected between the second oil port and the second reversing oil inlet, an oil inlet of the second check valve is connected to the second oil port, an oil outlet of the second check valve is connected to the second reversing oil inlet, the at least one actuating device includes a first actuating device and a second actuating device, a hydraulic actuator of the first actuating device is a hydraulic cylinder connected to the first heavy load, a hydraulic actuator of the second actuating device is a hydraulic motor connected to the second heavy load, and an oil outlet of the second check valve of the first actuating device is connected to an oil outlet of the second check valve of the second actuating device.
In some embodiments, the first pilot control end of the load control valve further comprises a second pilot port connected to the first oil port; or the size of the flow area of a communication channel of the first oil port and the second oil port is in direct proportion to the pressure of the pressure oil introduced into the first hydraulic control end.
In some embodiments, the directional control valve is a proportional directional control valve, the execution device further includes a pressure control valve having an oil inlet and an oil outlet respectively connected to the hydraulic pump and the second directional working oil port, a first end of the pressure control valve is provided with a first pressure hydraulic control port, a second end of the pressure control valve is provided with a second pressure hydraulic control port and a pressure spring, pressure oil introduced into the second pressure hydraulic control port and elastic force provided by the pressure spring make a spool of the pressure control valve tend to move in the same direction, pressure oil introduced into the first pressure hydraulic control port makes a spool of the pressure control valve tend to move in a direction opposite to a direction in which the spool of the pressure control valve tends to move by pressure oil introduced into the second pressure hydraulic control port and pressure oil introduced into the second pressure hydraulic control port, the spool of the pressure control valve is in a dynamic balance state under the action of the pressure oil introduced into the first pressure hydraulic control port, the pressure oil introduced into the second pressure hydraulic control port and the pressure spring, and a long-open state is between the oil inlet and the oil outlet of the pressure control valve, the execution device further includes a pressure selection valve, one of the pressure selection valve is connected to the first directional control valve, one of the oil inlet and the other one of the hydraulic control valve, the first directional control valve is connected to the pressure oil outlet, and the pressure oil port of the second pressure selection valve, and the other pressure selection valve is connected to the pressure selection valve, and the pressure oil port of the second hydraulic control valve, and the pressure selection valve is connected to the pressure selection valve.
In some embodiments, the hydraulic pump is a variable displacement pump, the heavy load control hydraulic system further includes a first hydraulic on-off valve, a first displacement adjusting device for introducing pressure oil to increase a displacement of the variable displacement pump, and a second displacement adjusting device for introducing pressure oil to decrease a displacement of the variable displacement pump, an oil inlet of the first displacement adjusting device is connected to an oil outlet of the variable displacement pump, the first hydraulic on-off valve includes a first on-off working port connected to the oil outlet of the variable displacement pump, a second on-off working port connected to an oil tank, and a third on-off working port connected to the second displacement adjusting device, the first on-off valve has a first on-off valve position state in which the first on-off working port and the third on-off working port are communicated, and a second on-off working port and a third on-off valve position state in which the second on-off working port and the third on-off working port are communicated, the first end of the first hydraulic control on-off valve is provided with a first on-off hydraulic control port connected with the oil outlet of the variable pump, the second end of the first hydraulic control on-off valve is provided with an adjustable elastic device and a second on-off hydraulic control port connected with the oil outlet of the pressure selection valve, pressure oil introduced into the first on-off hydraulic control port of the first hydraulic control on-off valve provides pressure for a valve core of the first hydraulic control on-off valve to enable the first hydraulic control on-off valve to have a tendency of switching to a first on-off valve position state, and pressure oil introduced into the second on-off hydraulic control port of the first hydraulic control on-off valve provides pressure for a valve core of the first hydraulic control on-off valve and elastic force provided for the valve core of the first hydraulic control on-off valve by the adjustable elastic device enables the first hydraulic control on-off valve to have a tendency of switching to a second on-off valve position state.
In some embodiments, the heavy load control hydraulic system further includes a second hydraulic on-off valve, a first on-off working oil port of the second hydraulic on-off valve is connected to the oil outlet of the variable displacement pump, a second on-off working oil port of the second hydraulic on-off valve and a third on-off working oil port of the second hydraulic on-off valve are connected between a third on-off working oil port of the first hydraulic on-off valve and an oil inlet of the second displacement adjusting device, a second on-off working oil port of the second hydraulic on-off valve is connected to a third on-off working oil port of the first hydraulic on-off valve, a third on-off working oil port of the second hydraulic on-off valve is connected to an oil inlet of the second displacement adjusting device, the second on-off valve has a third on-off valve position state in which the first on-off working oil port and the third on-off working oil port are communicated and a second on-off working oil port state in which the second on-off working oil port and the third hydraulic on-off valve is communicated to the second on-off valve spool, and the second hydraulic on-off valve has a tendency that the second on-off valve spool switches the second hydraulic on-off pressure of the second hydraulic on-off valve to the second hydraulic on-off valve, and the second hydraulic on-off valve.
In some embodiments, the first displacement adjustment device and/or the second displacement adjustment device comprises an elastic piston cylinder, the elastic piston cylinder comprises a cylinder barrel, a piston rod connected with the displacement adjustment mechanism of the variable displacement pump and a spring preventing the piston rod from extending relative to the cylinder barrel, and an oil inlet of the elastic piston cylinder is used for introducing pressure oil to enable the piston rod to extend relative to the cylinder barrel.
The invention discloses a construction machine in a second aspect, which comprises any heavy load control hydraulic system.
According to the heavy load control hydraulic system provided by the invention, the reversing valve, the load control valve and the first one-way valve are arranged to control the hydraulic executive component connected with the heavy load, when the heavy load is controlled to rise, the reversing oil inlet is communicated with the second reversing working oil port, the first working oil port is connected with the oil tank, the elastic force provided by the elastic control port of the load control valve to the valve core is larger than the pressure provided by the first hydraulic control port to the valve core, the first oil port and the second oil port of the load control valve are not communicated, and the pressure oil enters the second working oil port through the first one-way valve, so that the heavy load can be controlled to rise. When the heavy load is controlled to descend, the reversing oil inlet and the first reversing working oil port are arranged to be communicated, the first working oil port is communicated with pressure oil, the valve core of the load control valve is communicated with the first oil port and the second oil port under the action of the pressure oil of the first control port, the descending of the heavy load can be controlled, and the descending of the heavy load is more stable. Meanwhile, pressure oil generated in the heavy load descending process can enter the reversing oil inlet through the first oil port and the second oil port and finally enter the first working oil port to help open the load control valve, so that the energy of the pressure oil provided by the hydraulic pump is reduced, and the system is more energy-saving.
Other features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention and do not constitute a limitation of the invention. In the drawings:
fig. 1 is a schematic view of the structural principle of a heavy load control hydraulic system according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of the load control valve of FIG. 1;
FIG. 3 is a schematic view of the construction of the diverter valve shown in FIG. 1;
FIG. 4 is a schematic structural diagram of the hydraulic actuator shown in FIG. 1;
FIG. 5 is a schematic structural diagram of the pressure regulating valve shown in FIG. 1;
fig. 6 is a schematic structural diagram of the first hydraulic on-off valve and the second hydraulic on-off valve shown in fig. 1.
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, it need not be discussed further in subsequent figures.
In the description of the present invention, it should be understood that the terms "first", "second", etc. are used to define the components, which are only used for the convenience of distinguishing the corresponding components, and if not stated otherwise, the above terms have no special meanings, and therefore, should not be construed as limiting the scope of the present invention.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
For ease of description, spatially relative terms such as "over 8230 \ 8230;,"' over 8230;, \8230; upper surface "," above ", etc. may be used herein to describe the spatial relationship of one device or feature to another device or feature as shown in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary terms "at 8230; \8230; above" may include both orientations "at 8230; \8230; above" and "at 8230; \8230; below". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
As shown in fig. 1 to 4, the heavy load control hydraulic system of the present embodiment includes a hydraulic pump 1 and an actuator.
The hydraulic pump 1 is used to supply pressure oil to an actuator, and the hydraulic pump 1 is driven by an engine such as a diesel engine or an electric motor.
The actuating device comprises a hydraulic actuator 2, a reversing valve 3, a load control valve 4 and a first one-way valve 51.
The hydraulic executive component 2 comprises a first working oil port a1, a second working oil port a2 and a working component connected with a heavy load, when the working component acts in a first direction, the heavy load descends, when the working component acts in a second direction opposite to the first direction, the heavy load ascends, pressure oil introduced from the first working oil port a1 provides pressure enabling the working component to tend to act in the first direction, and pressure oil introduced from the second working oil port a2 provides pressure enabling the working component to tend to act in the second direction. In the embodiment shown in the figures, the hydraulic actuator 2 comprises a hydraulic cylinder and a hydraulic motor, and when the hydraulic actuator 2 comprises a hydraulic cylinder, the first direction is a direction from top to bottom along the height direction, and the actuator is a piston rod or a cylinder directly or indirectly connected with the heavy load. When the hydraulic actuator 2 comprises a hydraulic motor, the first direction is clockwise or counterclockwise, and the rotating shaft of the actuator in the hydraulic motor is indirectly connected with the gear of the heavy load.
As shown in fig. 3, the reversing valve 3 includes a first reversing working oil port b1 connected to the first working oil port a1, a second reversing working oil port b2 connected to the second working oil port a2, a reversing oil inlet b4 connected to the hydraulic pump 1, and a reversing oil outlet b3 connected to the oil tank, and has a first reversing state and a second reversing state, in the first reversing state, the first reversing working oil port b1 is communicated with the reversing oil outlet b3, and the second reversing working oil port b2 is communicated with the reversing oil inlet b4, and at this time, pressure oil output by the hydraulic pump enters from the reversing oil inlet b4, then is output from the second reversing working oil port b2, and then enters the second working oil port a2, so as to drive the heavy load to rise. In the second reversing state, the first reversing working oil port b1 is communicated with the reversing oil inlet b4, the second reversing working oil port b2 is communicated with the reversing oil outlet b3, and pressure oil output by the hydraulic pump enters from the reversing oil inlet b4, then is output from the first reversing working oil port b1, and then enters into the first working oil port a 1.
The load control valve 4 includes a first port c1, a second port c2, an elastic control end, and a first hydraulic control end located at the opposite side of the elastic control end. The elastic control end and the first hydraulic control end of the load control valve 4 are positioned on two sides of a valve core of the load control valve 4. The valve core of the load control valve 4 tends to move in a direction of closing the communication passage of the first port c1 and the second port c2 by the elastic force of the elastic control end, and the valve core of the load control valve 4 tends to move in a direction of opening the communication passage of the first port c1 and the second port c2 by the pressure oil introduced into the first hydraulic control end of the load control valve 4. The load control valve 4 may be a proportional valve or a non-proportional valve, when the load control valve 4 is a proportional valve, the larger the pressure of the pressure oil received by the first hydraulic control end is, the larger the flow area of the communication channel between the first oil port c1 and the second oil port c2 of the load control valve 4 is, when the load control valve 4 is a non-proportional valve, the larger the pressure of the pressure oil received by the first hydraulic control end reaches a certain size, and the communication channel between the first oil port c1 and the second oil port c2 of the load control valve 4 is opened. Whether the valve core of the load control valve 4 can open the communication passage of the first port c1 and the second port c2 or increase the flow area of the communication passage of the first port c1 and the second port c2 is mainly considered to compare the pressure received by the first hydraulic control end with the elastic force of the elastic control end, the absolute value of the pressure received by the first hydraulic control end and the elastic force of the elastic control end may be directly compared during comparison, or the absolute value may be compared after multiplying by a coefficient, for example, when the first hydraulic control end is provided with a pilot structure, the pressure received by the first hydraulic control end is pilot pressure, and the amplification coefficient needs to be multiplied by the pressure received by the first hydraulic control end when the ratio of the pressure received by the first hydraulic control end and the elastic force of the elastic control end is larger.
The first port c1 is connected to the second working port a2, and the first hydraulic control end of the load control valve 4 includes a first control port k1 connected to the first working port a1, that is, the pressure of the first working port a1 can be fed back to the first hydraulic control end of the load control valve 4 through the first control port k 1. The second oil port c2 is connected with the reversing oil inlet b4, so that when a heavy load descends, after the load control valve 4 is opened, a communication passage between the first oil port c1 and the second oil port c2 is communicated, pressure oil caused by descending of the heavy load flows in from the first oil port c1, flows out from the second oil port c2, enters the reversing oil inlet b4, and then flows into the first working oil port a1, and the opening of the communication passage between the first oil port c1 and the second oil port c2 is maintained, so that the pressure of the pressure oil output by the hydraulic pump can be reduced. The load control valve 4 of this embodiment may open the communication passage between the first port c1 and the second port c2 only when the first control port k1 has pressure oil, and when the pressure oil pressure of the first control port k1 is small or 0, the communication passage between the first port c1 and the second port c2 is kept closed under the elastic force of the elastic control end, so that when a heavy load generates a descending stall, the pressure of the pressure oil of the first working port a1 is rapidly decreased, the pressure oil pressure of the first control port k1 becomes small or 0, the flow area of the communication passage between the first port c1 and the second port c2 of the load control valve is decreased or the communication passage is closed, thereby preventing the heavy load from descending, when the heavy load speed returns to normal, the pressure of the pressure oil of the first working port a1 returns to normal, the communication passage between the first port c1 and the second port c2 of the load control valve 4 is opened or the flow area of the communication passage between the first port c1 and the second port c2 of the load control valve 4 is increased, and the heavy load continues to descend smoothly.
An oil inlet of the first check valve 51 is connected with the second reversing working oil port b2, and an oil outlet of the first check valve 51 is connected with a pipeline between the first oil port c1 and the second working oil port a 2. When the heavy load rises, the reversing valve 3 is in a first reversing state, the pressure oil output from the second reversing working oil port b2 enters the first check valve 51, is output to a pipeline between the first oil port c1 and the second working oil port a2, and then enters the hydraulic actuator from the second working oil port a2 to drive the actuator to move in the second direction, so that the heavy load rises.
The heavy load control hydraulic system of this embodiment, through setting up the switching-over valve 3, the hydraulic pressure executive 2 who is connected with the heavy load is controlled to load control valve 4 and first check valve 51, when controlling the heavy load and rise, through setting up switching-over oil inlet b4 and the intercommunication of second switching-over work oil mouth b2, first work oil mouth a1 is connected with the oil tank this moment, the elasticity that the elasticity control end of load control valve 4 provided the case is greater than the pressure that first liquid accuse end provided the case, do not pass through between the first hydraulic fluid port c1 and the second hydraulic fluid port c2 of load control valve 4, pressure oil gets into second work oil mouth a2 through first check valve 51, can control the heavy load and rise. When controlling the heavy load to descend, through setting up switching-over oil inlet b4 and the intercommunication of first switching-over work oil port b1, pressure oil lets in first work oil port a1, and first hydraulic fluid port c1 and second hydraulic fluid port c2 intercommunication under the effect of the pressure oil of first control mouth k1 of the case of load control valve 4 this moment can control the decline of heavy load, make the decline of heavy load more steady. Meanwhile, pressure oil generated in the heavy load descending process can enter the reversing oil inlet b4 through the first oil port c1 and the second oil port c2 and finally enter the first working oil port a1 to help open the load control valve 4, so that the energy of the pressure oil provided by the hydraulic pump 1 is reduced, and the system is more energy-saving.
In some embodiments, as shown in fig. 1, the actuating device further includes a second check valve 52 connected between the second oil port c2 and the second reversing oil inlet b4, an oil inlet of the second check valve 52 is connected to the second oil port c2, an oil outlet of the second check valve 52 is connected to the second reversing oil inlet b4, at least one of the actuating devices includes a first actuating device and a second actuating device, the hydraulic actuator 2 of the first actuating device is a hydraulic cylinder connected to the first heavy load, the hydraulic actuator 2 of the second actuating device is a hydraulic motor connected to the second heavy load, and an oil outlet of the second check valve 52 of the first actuating device is connected to an oil outlet of the second check valve 52 of the second actuating device. In the present embodiment, two actuators are provided, that is, two hydraulic actuators 2 and two corresponding load control valves 4 and directional control valves 3 are provided, and the heavy loads include a first heavy load and a second heavy load respectively connected to the two actuators 2. According to the embodiment, the pressure oil generated in the descending process of the first heavy load of the first executing device and the second heavy load of the second executing device can be output and recovered to the oil inlets of the corresponding reversing valves, and meanwhile, the pressure oil generated in the heavy load of the first executing device and the pressure oil generated in the descending process of the second executing device cannot enter the opposite hydraulic executing piece to interfere with the descending of the opposite heavy load.
In some embodiments, as shown in fig. 1 and fig. 2, the first pilot end of the load control valve 4 further includes a second pilot port k2 connected to the first port c1, that is, the load control valve 4 corresponds to the hydraulic actuator in fig. 1, in which the elastic force of the elastic pilot end of the load control valve 4 causes the valve core of the load control valve 4 to tend to close the communication channel between the first port c1 and the second port c2, and the pressure oil introduced into the second pilot port k2 causes the valve core of the load control valve 4 to tend to open the communication channel between the first port c1 and the second port c 2. The heavy load enables the pressure of the pressure oil output by the second working oil port a2 of the hydraulic cylinder to be introduced into the second control port k2 under the action of gravity, and when the pressure oil introduced into the first control port k1 is 0, the elastic force of the elastic control end is set to enable the communication channel between the first oil port c1 and the second oil port c2 to be kept closed in the state. When the pressure oil introduced into the first control port k1 is not 0, the load control valve 4 opens the load control valve 4 under the combined action of the pressure oil introduced into the first control port k1 and the pressure oil introduced into the second control port k2, so that the heavy load is stably reduced. The load control valve 4 of this embodiment is a non-proportional valve, that is, the flow area of the communication passage between the first port c1 and the second port c2 is not in direct proportion to the pressure applied to the first pilot control port.
Or, in some embodiments, as shown in fig. 1, the hydraulic actuator is a load control valve 4 corresponding to the hydraulic motor, the load control valve 4 is a proportional valve, the size of the flow area of the communication channel between the first oil port c1 and the second oil port c2 is proportional to the pressure of the pressure oil introduced into the first hydraulic control end, that is, the larger the pressure of the pressure oil introduced into the first working oil port a1 is, the larger the flow area of the communication channel between the first oil port c1 and the second oil port c2 is, so that the speed of the heavy load descending is faster, and when the pressure of the pressure oil introduced into the first working oil port a1 is, the smaller the flow area of the communication channel between the first oil port c1 and the second oil port c2 is, the slower the speed of the heavy load descending is, this embodiment can stably and effectively control the descending speed of the heavy load.
In some embodiments, as shown in fig. 1, 3 and 5, the directional valve 3 is a proportional directional valve, the actuator further includes a pressure regulating valve 6 having an oil inlet and an oil outlet respectively connected to the hydraulic pump 1 and the second directional working oil port b2, a first pressure hydraulic control port d1 is provided at a first end of the pressure regulating valve 6, a second pressure hydraulic control port d2 and a pressure spring are provided at a second end of the pressure regulating valve 6, the spool of the pressure regulating valve 6 tends to move in the same direction due to the pressure oil introduced into the second pressure hydraulic control port d2 and the elastic force provided by the pressure spring, the spool of the pressure regulating valve 6 tends to move in the opposite direction due to the pressure oil introduced into the first pressure hydraulic control port d1 and the spool of the pressure regulating valve 6 tends to move in the opposite direction due to the pressure oil introduced into the second pressure hydraulic control port d2, a valve core of the pressure regulating valve 6 is in a dynamic balance state under the action of pressure oil introduced into the first pressure hydraulic control port d1, pressure oil introduced into the second pressure hydraulic control port d2 and a pressure spring, and the oil inlet and the oil outlet of the pressure regulating valve 6 are in a long-open state (a communicated state), the execution device further comprises a pressure selection valve 9, in the embodiment shown in the figure, the pressure selection valve is a shuttle valve, namely, the pressure selection valve comprises two one-way valves with opposite oil outlets, one of the two oil inlets of the pressure selection valve is connected with a pipeline between the first reversing working oil port b1 and the first working oil port a1, the other of the two oil inlets is connected with a pipeline between the oil inlet of the first one-way valve 51 and the second reversing working oil port b2, the oil outlet of the pressure selection valve is connected with the second pressure hydraulic control port d2 of the pressure regulating valve 6, and the first pressure hydraulic control port d1 of the pressure regulating valve 6 is connected with the oil outlet of the pressure regulating valve 6. In this embodiment, the valve core of the pressure regulating valve 6 is kept balanced under the action of the first pressure hydraulic control port d1, the second pressure hydraulic control port d2 and the pressure spring, so that the oil inlet and the oil outlet of the pressure regulating valve 6 are kept communicated, and the valve core of the pressure regulating valve 6 is a proportional valve core, so as to adjust the size of the flow area between the oil inlet and the oil outlet of the pressure regulating valve 6. When the valve core of the pressure regulating valve 6 is balanced, the pressure of the first pressure hydraulic control port d1 is equal to the sum of the pressure of the second pressure hydraulic control port d2 and the elastic force of the pressure spring, so that the difference between the pressure of the first pressure hydraulic control port d1 and the pressure of the second pressure hydraulic control port d2 is the elastic force of the pressure spring and is a certain value, that is, a stable pressure difference can be maintained between the reversing oil inlet b4 of the reversing valve 3 and the first reversing working oil port b1 as well as between the reversing oil inlet b2 and the second reversing working oil port b2, because the reversing valve 3 is a proportional reversing valve, when the reversing valve 3 controls the heavy load to fall or rise, the displacement of the valve core of the reversing valve 3 is proportional to the flow area of a communication channel between the reversing oil inlet b4 and the first reversing working oil port b1 or between the second reversing working oil port b2, so that the flow of the pressure oil output to the first working oil port a1 or the second working oil port a2 can be proportional, and the reversing valve 3 can proportionally regulate the falling and rising of the heavy load in proportion.
In some embodiments, as shown in fig. 1 and fig. 6, the hydraulic pump 1 is a variable displacement pump, the heavy load control hydraulic system further includes a first pilot-controlled on-off valve 71, a first displacement regulating device 81 for introducing hydraulic oil to increase the displacement of the variable displacement pump, and a second displacement regulating device 82 for introducing hydraulic oil to decrease the displacement of the variable displacement pump, an oil inlet of the first displacement regulating device 81 is connected to an oil outlet of the variable displacement pump, the first pilot-controlled on-off valve 71 includes a first pilot-controlled on-off working port e1 connected to the oil outlet of the variable displacement pump, a second pilot-controlled on-off working port e2 connected to an oil tank, and a third pilot-controlled on-off working port e3 connected to the second displacement regulating device 82, the first on-off valve has a first on-off valve position state in which the first pilot-controlled on-controlled working port e1 and the third pilot-controlled working port e3 of the first pilot-controlled on-off valve are connected to the oil outlet of the variable displacement pump, and a second on-off valve position state in which the second pilot-controlled on-off working port e2 and the second pilot-controlled on-off valve 71 are connected to the second pilot-controlled on-off valve 71, and the first on-off valve 71, the first on-off valve 71 has a switching trend that the first on-off valve spool 71 of the first pilot-controlled on-off valve 71 and the second pilot-off valve 71 that the second pilot-controlled on-off working port e4 and the second pilot-controlled on-off valve 71 provides the pilot-off pressure switching valve 71 that the pilot-controlled on-off valve 71 and the second pilot-controlled on-off valve 71 that the second pilot-off valve 71 of the first pilot-controlled on-off valve 71 of the second pilot-controlled on-off valve 71. In this embodiment, when the pressure of the pressure oil output by the variable displacement pump is not matched with the pressure required by the load, the variable displacement pump can automatically adjust the pressure of the output pressure oil to match the pressure of the output pressure oil. When the pressure of the pressure oil output by the variable pump is greater than the pressure required by the load, that is, the pressure of the first on-off hydraulic control port e4 is greater than the pressure of the second on-off hydraulic control port e5 and the pressure of the adjustable elastic device, the first hydraulic control on-off valve 71 is switched to the first on-off valve position state, and the pressure oil output by the variable pump is output from the third on-off working port e3 to the second displacement adjusting device 82 through the first on-off working port e1, so that the displacement of the variable pump is reduced, and the pressure of the pressure oil output by the variable pump is reduced. When the pressure of the pressure oil output by the variable displacement pump is smaller than the pressure required by the load, that is, the pressure of the first on-off hydraulic control port e4 is smaller than the pressure of the second on-off hydraulic control port e5 and the pressure of the adjustable elastic device, the first hydraulic control on-off valve 71 is switched to the second on-off valve position state, the first on-off working port e1 is disconnected with the third on-off working port e3, the second displacement adjusting device 82 is connected with the oil tank, the displacement of the variable displacement pump is not reduced by the second displacement adjusting device 82, the displacement of the variable displacement pump is increased by the first displacement adjusting device, and the pressure of the pressure oil output by the variable displacement pump is increased.
In some embodiments, as shown in fig. 1 and 6, the heavy load control hydraulic system further includes a second hydraulic on-off valve 72, a first on-off working port e1 of the second hydraulic on-off valve 72 is connected to the oil outlet of the variable displacement pump, a second on-off working port e2 of the second hydraulic on-off valve 72 and a third on-off working port e3 of the second hydraulic on-off valve 72 are connected between a third on-off working port e3 of the first hydraulic on-off valve 71 and the oil inlet of the second displacement adjusting device 82, a second on-off working port e2 of the second hydraulic on-off valve 72 is connected to a third on-off working port e3 of the first hydraulic on-off valve 71, a third on-off working port e3 of the second hydraulic on-off valve 72 is connected to the oil inlet of the second displacement adjusting device 82, the second on-off valve has a third on-off valve position state in which a first on-off working oil port e1 and a third on-off working oil port e3 of the second on-off valve are communicated and a fourth on-off valve position state in which a second on-off working oil port e2 and a third on-off working oil port e3 of the second on-off valve are communicated, a third on-off hydraulic control port connected with an oil outlet of the variable displacement pump is arranged at a first end of the second hydraulic on-off valve 72, an adjustable elastic device is arranged at a second end of the second hydraulic on-off valve 72, the second hydraulic on-off valve 72 has a tendency of switching to the third on-off valve position state due to pressure provided by pressure oil introduced into the third on-off hydraulic control port to a valve core of the second hydraulic on-off valve 72, and the second hydraulic on-off valve 72 has a tendency of switching to the fourth on-off valve position state due to elastic force provided by the adjustable elastic device of the second hydraulic on-off valve 72. The second hydraulic on-off valve 72 in this embodiment limits the maximum pressure of the pressure oil output by the variable displacement pump. When the pressure oil output by the variable pump exceeds the maximum pressure, the second hydraulic on-off valve 72 is switched to the third on-off valve position state, and the pressure oil output by the variable pump enters the second displacement adjusting device 82, so that the displacement of the variable pump is reduced, and the pressure of the pressure oil output by the variable pump is reduced.
In some embodiments, as shown in fig. 1, the first displacement adjustment device 81 and/or the second displacement adjustment device 82 comprises an elastic piston cylinder, the elastic piston cylinder comprises a cylinder barrel, a piston rod connected with the displacement adjustment mechanism of the variable displacement pump and a spring for preventing the piston rod from extending relative to the cylinder barrel, and an oil inlet of the elastic piston cylinder is used for introducing pressure oil to enable the piston rod to extend relative to the cylinder barrel.
In some embodiments, the construction machine comprises any heavy load control hydraulic system.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention and not to limit it; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art will understand that: modifications of the embodiments of the invention or equivalent substitutions for parts of the technical features are possible; without departing from the spirit of the invention, it is intended to cover all modifications within the scope of the invention as claimed.
Claims (8)
1. A heavy load controlled hydraulic system, comprising:
a hydraulic pump for providing pressure oil;
at least one execution device comprising:
the hydraulic actuator comprises a first working oil port, a second working oil port and a working piece connected with a heavy load, wherein when the working piece acts in a first direction, the heavy load descends, when the working piece acts in a second direction opposite to the first direction, the heavy load ascends, pressure oil introduced from the first working oil port provides pressure enabling the working piece to tend to act in the first direction, and pressure oil introduced from the second working oil port provides pressure enabling the working piece to tend to act in the second direction;
the reversing valve comprises a first reversing working oil port connected with the first working oil port, a second reversing working oil port connected with the second working oil port, a reversing oil inlet connected with the hydraulic pump and a reversing oil outlet connected with an oil tank, and has a first reversing state and a second reversing state, wherein in the first reversing state, the first reversing working oil port is communicated with the reversing oil outlet, the second reversing working oil port is communicated with the reversing oil inlet, in the second reversing state, the first reversing working oil port is communicated with the reversing oil inlet, and the second reversing working oil port is communicated with the reversing oil outlet;
the load control valve comprises a first oil port, a second oil port, an elastic control end and a first hydraulic control end which is positioned on the opposite side of the elastic control end, wherein the elastic force of the elastic control end enables a valve core of the load control valve to tend to move towards the direction of closing a communication channel of the first oil port and the second oil port, pressure oil introduced into the first hydraulic control end of the load control valve enables the valve core of the load control valve to tend to move towards the direction of opening the communication channel of the first oil port and the second oil port, the first oil port is connected with the second working oil port, the first hydraulic control end of the load control valve comprises a first control port connected with the first working oil port, and the second oil port is connected with the reversing oil inlet;
an oil inlet of the first check valve is connected with the second reversing working oil port, and an oil outlet of the first check valve is connected with a pipeline between the first oil port and the second working oil port.
2. The heavy load control hydraulic system according to claim 1, wherein the actuator further comprises a second check valve connected between the second oil port and the second reversing oil inlet, an oil inlet of the second check valve is connected to the second oil port, an oil outlet of the second check valve is connected to the second reversing oil inlet, the at least one actuator comprises a first actuator and a second actuator, a hydraulic actuator of the first actuator is a hydraulic cylinder connected to the first heavy load, a hydraulic actuator of the second actuator is a hydraulic motor connected to the second heavy load, and an oil outlet of the second check valve of the first actuator is connected to an oil outlet of the second check valve of the second actuator.
3. The heavy load controlled hydraulic system of claim 1 or 2, wherein the first hydraulic control end of the load control valve further comprises a second control port connected to the first oil port; or the size of the flow area of the communication channel of the first oil port and the second oil port is in direct proportion to the pressure of the pressure oil introduced into the first hydraulic control end.
4. The heavy load control hydraulic system according to claim 1, wherein the directional control valve is a proportional directional control valve, the actuator further comprises a pressure regulating valve having an oil inlet and an oil outlet respectively connected to the hydraulic pump and the second directional working oil port, a first pressure hydraulic control port is provided at a first end of the pressure regulating valve, a second pressure hydraulic control port and a pressure spring are provided at a second end of the pressure regulating valve, the direction in which the spool of the pressure regulating valve tends to move is the same as the direction in which the spool of the pressure regulating valve tends to move due to pressure oil introduced into the second pressure hydraulic control port and elastic force provided by the pressure spring, the direction in which the spool of the pressure regulating valve tends to move is opposite to the direction in which the spool of the pressure regulating valve tends to move due to pressure oil introduced into the second pressure hydraulic control port, the valve core of the pressure regulating valve is in a dynamic balance state under the action of pressure oil introduced into the first pressure hydraulic control port, pressure oil introduced into the second pressure hydraulic control port and the pressure spring, and an oil inlet and an oil outlet of the pressure regulating valve are in a long opening state.
5. The heavy load controlled hydraulic system of claim 4, wherein the hydraulic pump is a variable displacement pump, the heavy load control hydraulic system further includes a first pilot-operated on-off valve, a first displacement adjusting device for introducing pressure oil to increase the displacement of the variable pump, and a second displacement adjusting device for introducing pressure oil to decrease the displacement of the variable pump, an oil inlet of the first displacement adjusting device is connected with an oil outlet of the variable pump, the first hydraulic control on-off valve comprises a first on-off working oil port connected with the oil outlet of the variable pump, a second on-off working oil port connected with the oil tank and a third on-off working oil port connected with the second displacement adjusting device, the first on-off valve has a first on-off valve position state in which a first on-off working oil port and a third on-off working oil port are communicated and a second on-off valve position state in which a second on-off working oil port and the third on-off working oil port are communicated, a first on-off hydraulic control port connected with the oil outlet of the variable pump is arranged at the first end of the first hydraulic control on-off valve, the second end of the first hydraulic control on-off valve is provided with an adjustable elastic device and a second on-off hydraulic control port connected with the oil outlet of the pressure selection valve, pressure oil introduced into the first on-off hydraulic control port of the first hydraulic control on-off valve provides pressure for a valve core of the first hydraulic control on-off valve to enable the first hydraulic control on-off valve to have a tendency of switching to a first on-off valve position state, and pressure oil introduced into the second on-off hydraulic control port of the first hydraulic control on-off valve provides pressure for the valve core of the first hydraulic control on-off valve and elastic force provided by the adjustable elastic device for the valve core of the first hydraulic control on-off valve enables the first hydraulic control on-off valve to have a tendency of switching to a second on-off valve position state.
6. The heavy load control hydraulic system according to claim 5, wherein the heavy load control hydraulic system further includes a second hydraulic on-off valve, a first on-off working port of the second hydraulic on-off valve is connected to an oil outlet of the variable displacement pump, a second on-off working port of the second hydraulic on-off valve and a third on-off working port of the second hydraulic on-off valve are connected between a third on-off working port of the first hydraulic on-off valve and an oil inlet of the second displacement adjusting device, a second on-off working port of the second hydraulic on-off valve is connected to a third on-off working port of the first hydraulic on-off valve, a third on-off working port of the second hydraulic on-off valve is connected to an oil inlet of the second displacement adjusting device, the second on-off valve has a third on-off valve position state in which the first on-off working port and the third on-off working port are communicated and a second on-off working port position state in which the second on-off working port and the second on-off working port are communicated, and a second on-off valve position state in which the second on-off working port of the second hydraulic on-off valve and the second hydraulic on-off valve is provided with a second on-off elastic pressure switching valve spool of the second hydraulic on-off valve, and the second hydraulic on-off valve is provided with a second on-off pressure switching trend of the second hydraulic on-off valve.
7. The heavy load control hydraulic system of claim 5, wherein the first displacement adjustment device and/or the second displacement adjustment device comprises an elastomeric piston cylinder, the elastomeric piston cylinder comprising a cylinder barrel, a piston rod connected to the displacement adjustment mechanism of the variable displacement pump, and a spring preventing the piston rod from extending relative to the cylinder barrel, an oil inlet of the elastomeric piston cylinder being adapted to receive pressurized oil to extend the piston rod relative to the cylinder barrel.
8. A working machine, characterized in that it comprises a heavy load control hydraulic system according to any one of claims to 7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211181803.2A CN115573955A (en) | 2022-09-27 | 2022-09-27 | Heavy load control hydraulic system and engineering machinery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211181803.2A CN115573955A (en) | 2022-09-27 | 2022-09-27 | Heavy load control hydraulic system and engineering machinery |
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| Publication Number | Publication Date |
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| CN115573955A true CN115573955A (en) | 2023-01-06 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211181803.2A Pending CN115573955A (en) | 2022-09-27 | 2022-09-27 | Heavy load control hydraulic system and engineering machinery |
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| Country | Link |
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| CN (1) | CN115573955A (en) |
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2022
- 2022-09-27 CN CN202211181803.2A patent/CN115573955A/en active Pending
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