CN112173994A - Control valve unit, hydraulic control loop and engineering equipment with telescopic crane boom - Google Patents
Control valve unit, hydraulic control loop and engineering equipment with telescopic crane boom Download PDFInfo
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- CN112173994A CN112173994A CN202010991630.5A CN202010991630A CN112173994A CN 112173994 A CN112173994 A CN 112173994A CN 202010991630 A CN202010991630 A CN 202010991630A CN 112173994 A CN112173994 A CN 112173994A
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- Prior art keywords
- valve
- oil
- control
- port
- control valve
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B66—HOISTING; LIFTING; HAULING
- B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
- B66C23/00—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes
- B66C23/62—Constructional features or details
- B66C23/64—Jibs
- B66C23/70—Jibs constructed of sections adapted to be assembled to form jibs or various lengths
- B66C23/701—Jibs constructed of sections adapted to be assembled to form jibs or various lengths telescopic
- B66C23/705—Jibs constructed of sections adapted to be assembled to form jibs or various lengths telescopic telescoped by hydraulic jacks
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B66—HOISTING; LIFTING; HAULING
- B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
- B66C23/00—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes
- B66C23/88—Safety gear
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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
- F15B1/00—Installations or systems with accumulators; Supply reservoir or sump assemblies
- F15B1/02—Installations or systems with accumulators
- F15B1/024—Installations or systems with accumulators used as a supplementary power source, e.g. to store energy in idle periods to balance pump load
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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
- F15B1/00—Installations or systems with accumulators; Supply reservoir or sump assemblies
- F15B1/02—Installations or systems with accumulators
- F15B1/027—Installations or systems with accumulators having accumulator charging 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
- F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
- F15B11/08—Servomotor systems without provision for follow-up action; Circuits therefor with only one servomotor
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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
- F15B13/04—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor
- F15B13/044—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by electrically-controlled means, e.g. solenoids, torque-motors
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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
- F15B21/08—Servomotor systems incorporating electrically operated control means
- F15B21/087—Control strategy, e.g. with block diagram
Abstract
The invention relates to a hydraulic control system of a crane boom, and discloses a control valve unit, which comprises a control valve working pipeline, a direction control valve, a first pressure control valve, a second pressure control valve and a control valve oil return pipeline, wherein the control valve working pipeline is connected with a first working oil port and a second working oil port; the first pressure control valve is located on an oil path between the second working oil port and the energy accumulator, the energy accumulator and an oil supplementing check valve are further installed between the second working oil ports, so that hydraulic oil in the energy accumulator flows to the second working oil ports in a single direction, and the second pressure control valve is located on the oil path between the second working oil ports and the control valve oil return pipeline. The invention also discloses a hydraulic control loop and engineering equipment with the telescopic crane boom. The invention can be used for preventing the telescopic arm from moving forward during emergency braking and eliminating potential safety hazards.
Description
Technical Field
The invention relates to a hydraulic control system of a crane arm, in particular to a control valve unit, and further relates to a hydraulic control circuit with the control valve unit and engineering equipment with a telescopic crane arm.
Background
The telescopic mechanism of the medium and small tonnage truck crane mainly controls the telescopic movement of the crane boom through the extension and retraction of the oil cylinder, meanwhile, the crane boom can carry out lifting load at any position in the extension and retraction due to the characteristics of the telescopic mechanism, the oil cylinder retracts during driving, and the retracted crane boom is placed on the crane boom support to reduce the length of the whole truck, thereby ensuring the safety and the flexibility of driving.
In the prior art, after the oil cylinder retracts, the main valve keeps a neutral position, and the neutral position of the main valve can ensure that hydraulic oil cannot flow out of the oil cylinder through the main valve in the running process of the crane.
Specifically, fig. 1 shows a conventional hydraulic telescopic control circuit, in which a hydraulic oil pump 1a supplies oil to a telescopic cylinder 3a through a main valve 2a to drive the telescopic cylinder 3a to perform telescopic movement, and the main valve 2a keeps a neutral position during crane traveling; braking suddenly in the driving process, because the effect of inertia, the jib has the trend of stretching out outward, and the cylinder liner that drives telescopic cylinder 3a also has the trend of stretching out outward, exerts pressure to telescopic cylinder 3 a's the hydraulic oil that has the pole intracavity, and the hydraulic oil that has the pole intracavity can be revealed via main valve 2a to the phenomenon that the jib scurries forward appears, influences the normal driving of hoist, has the potential safety hazard.
Disclosure of Invention
The invention aims to provide a control valve unit which can be used for preventing a telescopic arm from moving forward during emergency braking and eliminating potential safety hazards.
Further, the present invention is directed to provide a hydraulic control circuit that can prevent a forward movement of a telescopic arm due to an inertial force during emergency braking, and eliminate potential safety hazards.
In addition, the technical problem to be solved by the invention is to provide engineering equipment with a telescopic boom, which can prevent the forward movement of the telescopic boom caused by inertia force during emergency braking and eliminate potential safety hazards.
In order to solve the technical problem, the invention provides a control valve unit, which comprises a control valve working pipeline, a direction control valve, a first pressure control valve, a second pressure control valve and a control valve oil return pipeline, wherein the control valve working pipeline is connected with a first working oil port and a second working oil port; the first pressure control valve is located on an oil path between the second working oil port and the energy accumulator, the energy accumulator and an oil supplementing check valve are further installed between the second working oil ports, so that hydraulic oil in the energy accumulator flows to the second working oil ports in a single direction, and the second pressure control valve is located on the oil path between the second working oil ports and the control valve oil return pipeline.
Preferably, the first pressure control valve comprises a first cartridge valve and a pressure reducing valve, and the pressure reducing valve is installed on an oil path between a control cavity of the first cartridge valve and the accumulator; the energy accumulator is connected with the second working oil port through the first cartridge valve.
Preferably, the second pressure control valve comprises a second cartridge valve and a first overflow valve, a control cavity of the second cartridge valve is connected with the control valve oil return pipeline through the first overflow valve, and the second working oil port is connected with the control valve oil return pipeline through the second cartridge valve.
More preferably, the second pressure control valve further includes a pilot oil path switching valve and a second overflow valve connected to the control valve return line, the first overflow valve and the second overflow valve are connected to a control chamber of the second cartridge valve through the pilot oil path switching valve, and the control chamber of the second cartridge valve can be selectively communicated with the first overflow valve or the second overflow valve through the pilot oil path switching valve.
Preferably, the directional control valve comprises a third cartridge valve and an electromagnetic directional valve, the third cartridge valve comprises a first main oil port connected with the first working oil port, a second main oil port connected with the second working oil port and a control cavity connected with the first oil port of the electromagnetic directional valve, and the electromagnetic directional valve comprises the first oil port, a second oil port connected with the second main oil port of the third cartridge valve and a third oil port connected with the control valve oil return pipeline, so that the on-off of the third cartridge valve can be controlled.
Preferably, the directional control valve is an oil passage cut-off valve.
Specifically, the oil passage on-off valve is a two-position two-way valve so as to control the on-off of the working pipeline of the control valve.
The invention also discloses a hydraulic control loop, which comprises the control valve unit, an operating valve and a hydraulic pump connected with the operating valve in any one of the technical schemes, wherein the operating valve is connected with a rod cavity of a hydraulic oil cylinder through the control valve unit, the operating valve is connected with a rodless cavity of the hydraulic oil cylinder through a balance valve, and the control end of the balance valve is connected with the rod cavity of the hydraulic oil cylinder.
Preferably, the control valve comprises a control valve oil inlet path, a control valve oil return path, an oil inlet connected with the control valve oil inlet path, an oil return port connected with the control valve oil return path, a first oil port connected with the control valve unit, a second oil port connected with the balance valve, a constant pressure differential valve and a main valve located between the control valve oil inlet path and the control valve oil return path, the constant pressure differential valve is located on the oil path between the control valve oil inlet path and the control valve oil return path, the main valve is respectively connected with the first oil port and the second oil port of the control valve through a flow compensation valve, and the hydraulic pump is connected with the oil inlet of the control valve.
Furthermore, a back pressure valve is arranged on the operating valve oil return oil way, a main overflow valve is further arranged between the operating valve oil inlet oil way and the operating valve oil return oil way, and a secondary overflow valve is arranged between a second oil port of the operating valve and the operating valve oil return oil way.
The invention also discloses engineering equipment with the telescopic crane boom, which comprises the hydraulic control circuit in any one of the technical schemes.
Through the technical scheme, the invention has the following beneficial effects:
in the basic technical scheme of the invention, when the control valve unit is applied to a hydraulic control loop for controlling the telescopic operation of the crane boom, the conventional telescopic operation of the crane boom can be realized by hydraulic oil flowing through a first working oil port of the control valve unit, a direction control valve on a control valve working pipeline and a second working oil port; when the equipment takes place the braking in the in-process of traveling, first pressure control valve and second pressure control valve keep the pressure of second work hydraulic fluid port, control hydraulic cylinder's the oil extraction pressure that has the pole chamber promptly, hydraulic oil can't flow back to hydraulic tank under the effect of inertial force in the pole chamber of control hydraulic cylinder, simultaneously, the accumulator can supplement hydraulic oil that has the pole chamber of hydraulic cylinder to leak, hydraulic cylinder can't stretch out, flexible arm also can't stretch out, thereby the flexible arm forward scurrying phenomenon that arouses because of inertial force during the solution braking, eliminate the potential safety hazard.
Additional features and advantages of the invention will be set forth in the detailed description which follows.
Drawings
FIG. 1 is a hydraulic schematic of a hydraulic telescoping control circuit of a prior art crane;
FIG. 2 is a hydraulic schematic of the hydraulic control circuit of the exemplary embodiment of the present invention;
fig. 3 is a hydraulic schematic of a control valve unit according to an embodiment of the present invention.
Description of the reference numerals
11 control valve working pipeline 12 control valve oil return pipeline
13 accumulator 14 oil-supplementing one-way valve
P1 first working oil port P2 second working oil port
21 first cartridge valve 22 pressure reducing valve
23 second cartridge valve 24 first overflow valve
25 pilot oil passage switching valve 26 second relief valve
27 third Cartridge valve A1 first Main Port of third Cartridge valve
Second main oil port 28 electromagnetic directional valve of A2 third cartridge valve
First oil port of B1 electromagnetic directional valve and second oil port of B2 electromagnetic directional valve
Oil inlet of C1 operating valve and oil return port of C2 operating valve
First port of C3 pilot valve C4 pilot valve second port
31 operating valve oil inlet path 32 operating valve oil return path
33 constant pressure differential valve 34 main valve
35 flow compensating valve 36 back pressure valve
37 primary overflow valve 38 secondary overflow valve
4 hydraulic pump 5 hydraulic oil cylinder
Hydraulic oil pump with 6 balance valve 1a in prior art
2a main valve 3a Prior Art Telescopic Cylinder
Detailed Description
The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.
Furthermore, the terms "first", "second", "third" are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated, and therefore the features defined "first", "second", "third" may explicitly or implicitly include one or more of the features described.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "disposed," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; either directly or indirectly through intervening media, either internally or in any combination thereof. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
First, it should be noted that the hydraulic control circuit of the present invention belongs to the hydraulic field, and for those skilled in the art, the substantial technical idea thereof lies in the hydraulic connection relationship. The related hydraulic components, such as the directional valve, the balance valve, the check valve, the relief valve, the hydraulic pump, etc., are well known to those skilled in the art and are common components in existing hydraulic systems, and therefore, they will be described only briefly below. After understanding the technical concept of the present invention, those skilled in the art may also simply replace oil passages or valves, etc. to implement the function of the hydraulic control circuit of the present invention, which also belongs to the protection scope of the present invention.
As shown in fig. 2 and 3, the control valve unit according to the basic embodiment of the present invention includes a control valve working line 11 connecting a first working port P1 and a second working port P2, a directional control valve installed on the control valve working line 11, a first pressure control valve, a second pressure control valve, and a control valve return line 12; the first pressure control valve is located on an oil path between the second working oil port P2 and the accumulator 13, the oil supplementing check valve 14 is further installed between the accumulator 13 and the second working oil port P2 so that hydraulic oil in the accumulator 13 can flow to the second working oil port P2 in a single direction, and the second pressure control valve is located on an oil path between the second working oil port P2 and the control valve oil return pipeline 12.
With respect to the prior art hydraulic telescoping control circuit shown in fig. 1, the research and development personnel of the project have found through a great deal of analysis and research that: in the process of extending the telescopic wall, the engine drives the hydraulic oil pump 1a to provide hydraulic oil, the hydraulic oil is reversed by the main valve 2a and enters the rodless cavity of the telescopic oil cylinder 3a, and the hydraulic oil in the rod cavity of the telescopic oil cylinder 3a flows back to the oil tank through the main valve 2a to finish the extending action; in the retracting process of the telescopic arm, the engine drives the hydraulic oil pump 1a to provide hydraulic oil, the hydraulic oil is reversed through the main valve 2a and enters the rod cavity of the telescopic oil cylinder 3a, and the hydraulic oil in the rod cavity of the telescopic oil cylinder 3a opens the balance valve through the control oil port of the balance valve, so that the hydraulic oil in the rodless cavity of the telescopic oil cylinder 3a flows back to the oil tank through the main valve 2a to finish the retracting action; after the retraction action is finished, the telescopic boom is placed on the boom support through the amplitude variation oil cylinder so as to meet the traveling requirements; in the process of driving, the telescopic boom and the lower crane have the same speed, when braking occurs, the lower crane has acceleration opposite to the driving direction due to the friction effect of the brake, the other mechanisms of the upper crane are rigidly connected with the lower crane, so the whole mechanism is decelerated together with the lower crane, and the telescopic mechanism cannot be rigidly connected with the telescopic boom due to the particularity of crane operation (matching with a load hoisting working condition needs to be completed through the telescopic boom in the crane operation process, and certain road driving related regulations need to be met after the hoisting is completed). The state of the telescopic oil cylinder 3a after the telescopic arm retracts is that the piston and the cylinder bottom are in a mechanical limit state, the pressure in a rod cavity of the telescopic oil cylinder 3a is determined by a telescopic arm overflow valve, and meanwhile, a main valve 1a is usually used as a corresponding control element due to the telescopic performance requirement of the telescopic arm in the use process; during the braking process, the telescopic arm has certain inertia, and during the kinetic energy releasing process, the telescopic arm drives the cylinder sleeve of the telescopic oil cylinder 3a to move, the pressure in the rod cavity of the telescopic oil cylinder 3a rises, at the moment, hydraulic oil in the rod cavity of the telescopic oil cylinder 3a is compressed, and part of the hydraulic oil leaks back through the main valve 1a, so that the phenomenon that the telescopic arm moves forwards due to the inertia force is caused.
The control valve unit is applied to a hydraulic control loop for controlling the telescopic boom, referring to fig. 2 and 3, in the telescopic boom extending process, an engine drives a hydraulic pump 4 to provide hydraulic oil, and the hydraulic oil enters a rodless cavity of a hydraulic oil cylinder 5 through a control valve 3 and a balance valve 6 to complete extending action; in the retraction process of the telescopic boom, the engine drives the hydraulic pump 4 to provide hydraulic oil, and the hydraulic oil enters a rod cavity of the hydraulic oil cylinder 5 through a direction control valve and a balance valve 6 of a control valve unit to finish retraction; after the retraction action of the telescopic boom is finished, the telescopic boom is placed on a boom support to meet the requirement of traveling; the hydraulic oil continuously enters a rod cavity of the hydraulic oil cylinder 5, so that a piston and the cylinder bottom of the hydraulic oil cylinder 5 are in a mechanical limit state of close contact, and then the hydraulic oil enters an energy accumulator 13 through a directional control valve; in the driving process, the direction control valve is in a disconnected state, the first pressure control valve and the second pressure control valve maintain the pressure of a second working oil port, and the second working oil port is communicated with a rod cavity of the hydraulic oil cylinder 5, namely, the first pressure control valve and the second pressure control valve control the pressure of the rod cavity of the hydraulic oil cylinder; wherein, the second pressure control valve is connected with the control valve oil return pipeline 12, which can prevent the oil pressure in the pipe system from being too high, and plays the role of overload protection.
As a specific embodiment of the first pressure control valve, the first pressure control valve includes a first cartridge valve 21 and a pressure reducing valve 22, one end of the pressure reducing valve 22 is connected to a control chamber of the first cartridge valve 21 through a throttle valve so as to be capable of controlling the pressure of the control chamber of the first cartridge valve 21, the other end of the pressure reducing valve is connected to an oil path between the energy accumulator 13 and the oil compensating check valve 14, and two working oil ports of the first cartridge valve 21 are respectively connected to the energy accumulator 13 and a second working oil port P2; the first cartridge valve 21 is preferably a cartridge with a valve core provided with a bottom damping hole, the pressure of a control cavity of the first cartridge valve 21 is controlled by a pressure reducing valve 22, when the pressure of a working oil port of the first cartridge valve 21 connected with a second working oil port P2 of a control valve unit is greater than the pressure of the control cavity of the first cartridge valve 21, two working oil ports of the first cartridge valve 21 are communicated, and hydraulic oil enters the energy accumulator 13; the first cartridge valve 21 can ensure the pressure at the second working port P2 of the control valve unit, thereby controlling the pressure of the rod chamber of the hydraulic oil cylinder 5 and preventing the forward movement of the telescopic arm caused by inertia force during emergency braking.
As a specific example of the second pressure control valve, the second pressure control valve includes a second cartridge valve 23 and a first overflow valve 24, a second working port P2 of the control valve unit is connected with the control valve return line 12 through the second cartridge valve 23, and meanwhile, a control cavity of the second cartridge valve 23 is connected with the control valve return line 12 through the first overflow valve 24; the second cartridge valve 23 is preferably a cartridge with a bottom damping hole in a valve core, pressure in a control cavity of the second cartridge valve 23 is controlled by the first overflow valve 24, when pressure at a second working oil port P2 of the control valve unit is greater than pressure in the control cavity of the second cartridge valve 23, two working oil ports of the second cartridge valve 23 are communicated, and part of hydraulic oil can enter the control valve oil return pipeline 12 through the second cartridge valve 23 and flow back to the oil tank, so that system safety is ensured.
Further, the second pressure control valve may further include a pilot oil path switching valve 25 and a second relief valve 26, the second relief valve 26 is connected to the control valve return line 12, the first relief valve 24 and the second relief valve 26 are connected to the control chamber of the second cartridge valve 23 through the pilot oil path switching valve 25, a throttle is further provided between the pilot oil path switching valve 25 and the control chamber of the second cartridge valve 23 to control switching of the pilot oil path switching valve 25, the control chamber of the second cartridge valve 23 may be selectively communicated with the first relief valve 24 or the second relief valve 26, when the control chamber of the second cartridge valve 23 is communicated with the first relief valve 24, the pressure of the control chamber of the second cartridge valve 23 is controlled by the first relief valve 24, when the control chamber of the second cartridge valve 23 is communicated with the second relief valve 26, the pressure of the control chamber of the second cartridge valve 23 is controlled by the second relief valve 26, so that the second cartridge valve 23 functions as a secondary relief, ensuring pressure during retraction; the pilot oil path switching valve 25 may be a two-position three-way valve or other hydraulic valves capable of achieving the same function, and is preferably an electromagnetic proportional two-position three-way valve; of course, other control means may be used, such as hydraulic, pneumatic, electro-hydraulic, etc.
In a specific embodiment, the directional control valve may have various structural forms, for example, the directional control valve may include a third cartridge valve 27 and a solenoid directional valve 28, a first main port a1 of the third cartridge valve 27 is connected to a first working port P1, a second main port a2 of the third cartridge valve 27 is connected to a second working port P2, a control chamber of the third cartridge valve 27 is connected to a first port B1 of the solenoid directional valve 28, a second port B2 of the solenoid directional valve 28 is connected to a second working port P2, and a third port B3 of the solenoid directional valve 28 is connected to the control valve return line 12; the electromagnetic directional valve 28 may be a two-position three-way valve or other hydraulic valve capable of performing the same function, preferably an electromagnetic proportional two-position three-way valve; when the first oil port B1 of the electromagnetic directional valve 28 is connected with the third oil port B3 thereof, the control cavity of the third cartridge valve 27 is connected with the oil tank through the control valve oil return pipeline 12, so that the first main oil port A1 of the third cartridge valve 27 is communicated with the second main oil port A2 thereof, and the rod cavity of the hydraulic oil cylinder 5 can be communicated with the control valve 3, so that the control valve 3 can drive the hydraulic oil cylinder 5 to do telescopic action; when the first oil port B1 of the electromagnetic directional valve 28 is connected with the second oil port B2, the first main oil port A1 of the third cartridge valve 27 is disconnected with the second main oil port A2, the rod cavity of the cut-off hydraulic oil cylinder 5 is connected with the operating valve 3, the pressure in the rod cavity of the hydraulic oil cylinder 5 is controlled through the pressure maintaining effect of the first cartridge valve 21 and the safety effect of the second cartridge valve 23, hydraulic oil in the rod cavity of the hydraulic oil cylinder 5 cannot flow back to the hydraulic oil tank under the action of inertia force, the phenomenon of forward movement of a telescopic arm caused by the inertia force during emergency braking is solved, and potential safety hazards are eliminated. For another example, the directional control valve may be an oil path on-off valve for controlling the on-off of the oil path between the hydraulic oil cylinder 5 and the operating valve 3; specifically, the hydraulic control system can be a two-position two-way valve, and the on-off of an oil path between the hydraulic oil cylinder 5 and the operating valve 3, namely the on-off of a working pipeline 11 of the control valve, is controlled by switching the two-position two-way valve; the valve can also be a two-position three-way valve or a three-way valve, and the on-off control of the control valve working pipeline 11 can also be realized.
The control valve unit of the present invention is applied to a specific hydraulic control circuit in order to better understand the technical concept of the present invention.
Referring to fig. 2, the second working oil port P2 of the control valve unit is connected with the rod cavity of the hydraulic cylinder 5, the first working oil port P1 of the control valve unit is connected with the pilot valve 3, the oil inlet C1 of the pilot valve 3 is connected with the hydraulic pump 4, the pilot valve 3 is connected with the rodless cavity of the hydraulic cylinder 5 through the balance valve 6, and the control end of the balance valve 6 is connected with the rod cavity of the hydraulic cylinder 5.
In the retracting process of the telescopic boom, the engine drives the hydraulic pump 4 to provide hydraulic oil, the electromagnetic directional valve 28 is located at the left position, so that the first main oil port a1 of the third cartridge valve 27 is communicated with the second main oil port a2 thereof, the hydraulic oil enters the rod cavity of the hydraulic cylinder 5 through the operating valve 3 and the third cartridge valve 27, meanwhile, the hydraulic oil opens the balance valve 6 through the control end of the balance valve 6, so that the hydraulic oil in the rod-free cavity of the hydraulic cylinder 5 flows back to the oil tank through the balance valve and the operating valve 3; at the moment of retraction of the telescopic arm, the pressure rise rate in the rod cavity of the hydraulic oil cylinder 5 is high, the valve core of the first cartridge valve 21 is opened by pressure pulse, hydraulic oil enters the energy accumulator 13, the energy accumulator 13 plays a role in filtering, pressure pulsation of the rod cavity of the hydraulic oil cylinder 5 at the moment of retraction of the telescopic arm is reduced, correspondingly, fluctuation of the position of the valve core at the moment of opening of the balance valve 6 is reduced, and the smoothness of the telescopic arm during retraction is enhanced.
In addition, a pressure detection device, such as a hydraulic sensor, may be further disposed at the second working port P2 of the control valve unit, and a control element, such as a PLC, a single chip microcomputer, or the like, may control the direction change of the pilot oil path switching valve 25 or the electromagnetic directional valve 28 according to a pressure signal at the second working port P2 of the control valve unit, so as to control the extension and retraction of the telescopic arm and prevent the forward movement of the telescopic arm during emergency braking. Wherein the sensor and the control element belong to conventional elements, the realization of the control technology is relatively mature under the technical teaching of the invention.
As a specific embodiment of the operating valve, the operating valve 3 includes an operating valve oil inlet path 31, an operating valve oil return path 32, an oil inlet C1, an oil return port C2, a first port C3, a second port C4, and a main valve 34, the operating valve oil inlet path 31 is connected to the oil inlet C1 of the operating valve 3, the operating valve oil return path 32 is connected to the oil return port C2 of the operating valve 3, the first port C3 of the operating valve 3 is connected to the first working port P1 of the control valve unit, and the second port C4 of the operating valve 3 is connected to the rodless cavity of the hydraulic cylinder 5 through the balance valve 6; the main valve 34 is located between the pilot valve oil inlet path 31 and the pilot valve oil return path 32, a constant differential pressure valve 33 is further arranged between the pilot valve oil inlet path 31 and the pilot valve oil return path 32, and the main valve 34 is respectively connected with the first oil port C3 and the second oil port C4 of the pilot valve 3 through the flow compensation valve 35; in a standby state, the hydraulic pump 4 provides hydraulic oil, the main valve 34 is in a middle position, and the hydraulic oil flows back to the oil tank through the constant pressure difference valve 33, the operating valve oil return oil path 32 and the back pressure valve 36 on the operating valve oil return oil path 32; in the extending process of the telescopic boom, the main valve 34 is reversed, hydraulic oil enters a rodless cavity of the hydraulic oil cylinder 5 through the main valve 34, the flow compensation valve 35 and the balance valve 6, the electromagnetic directional valve 28 is reversed, the first main oil port A1 of the third cartridge valve 27 is communicated with the second main oil port A2, the hydraulic oil in the rod cavity of the hydraulic oil cylinder 5 flows back to an oil tank through the third cartridge valve 27, the main valve 34 and the back pressure valve 36, and the extending action of the telescopic boom is completed; in the retracting process of the telescopic boom, hydraulic oil enters a rod cavity of the hydraulic oil cylinder 5 through the main valve 34, the flow compensation valve 35 and the third cartridge valve 27, and meanwhile, the balance valve 6 is opened by the hydraulic oil through the control end of the balance valve 6, so that the hydraulic oil in the rod-free cavity of the hydraulic oil cylinder 5 flows back to an oil tank through the balance valve 6 and the main valve 34 to finish the retracting action of the telescopic boom; the hydraulic oil continuously enters the rod cavity of the hydraulic oil cylinder 5, so that the piston and the cylinder bottom of the hydraulic oil cylinder 5 are in a mechanical limit state of close contact, then the valve core of the first cartridge valve 21 is opened, the hydraulic oil enters the energy accumulator 13, after a certain pressure is reached, the pressure of the control cavity of the second cartridge valve 23 reaches the pressure for opening the first overflow valve 24, and at the moment, the pressure in the rod cavity of the hydraulic oil cylinder 5 is the pressure to be kept in a driving state; then the electromagnetic directional valve 28 loses power and cuts off the control valve working pipeline 11, and the arrangement can effectively prevent the forward movement of the telescopic arm during emergency braking. In addition, a main overflow valve 37 is further arranged between the operating valve oil inlet path 31 and the operating valve oil return path 32 to ensure system safety, and a secondary overflow valve 38 is arranged between the second port C4 of the operating valve 3 and the operating valve oil return path 32 to limit pressure during extension of the telescopic boom.
In order to facilitate a more thorough understanding of the technical concepts and advantages of the hydraulic control circuit of the present invention, a relatively comprehensive configuration of the hydraulic control circuit of the relatively preferred features of the present invention will be described below with reference to fig. 2 and 3.
As shown in fig. 2 and 3, the hydraulic pump 4 is connected to the pilot valve oil inlet path 31 through an oil inlet C1 of the pilot valve 3, a main valve 34 is disposed on an oil path between the pilot valve oil inlet path 31 and the pilot valve oil return path 32, a constant pressure difference valve 33 and a main overflow valve 37 are further installed on an oil path between the pilot valve oil inlet path 31 and the pilot valve oil return path 32, the pilot valve oil return path 32 is connected to an oil tank, and a back pressure valve 36 is installed thereon; the main valve 34 is respectively connected with the first port C3 and the second port C4 of the pilot valve 3 through a flow compensation valve 35, the second port C4 of the pilot valve 3 is connected with the balance valve 6, the balance valve 6 is connected with the rodless cavity of the hydraulic oil cylinder 5, and the first port C3 of the longitudinal valve 3 is connected with the first working port P1 of the control valve unit; a third cartridge valve 27 is installed on a control valve working pipeline 11 of the control valve unit, a first main oil port A1 of the third cartridge valve 27 is connected with a first working oil port P1, a second main oil port A2 of the third cartridge valve 27 is connected with a second working oil port P2, a control cavity of the third cartridge valve 27 is connected with a first oil port B1 of the electromagnetic directional valve 28, a second oil port B2 of the electromagnetic directional valve 28 is connected with a second main oil port A2 of the third cartridge valve 27, and a third oil port B3 of the electromagnetic directional valve 28 is connected with a control valve oil return pipeline 12; the second working oil port P2 of the control valve unit is respectively connected with the first cartridge valve 21 and the second cartridge valve 23, the first cartridge valve 21 is connected with the energy accumulator 13, the control cavity of the first cartridge valve 21 is connected with the pressure reducing valve 22 to limit the pressure of the control cavity of the first cartridge valve 21, when the pressure of the second working oil port P2 of the control valve unit is greater than the pressure of the control cavity of the first cartridge valve 21, hydraulic oil can enter the energy accumulator 13 through the first cartridge valve 21, and the energy accumulator 13 is connected with the second working oil port P2 of the control valve unit through the oil supplementing one-way valve 14 to supplement the hydraulic oil leaked from the rod cavity of the hydraulic oil cylinder 5; the second cartridge valve 23 is connected with the control valve return line 12, a pilot oil path switching valve 25 is connected to a control cavity of the second cartridge valve 23, the pilot oil path switching valve 25 is respectively connected with a first overflow valve 24 and a second overflow valve 26, and the first overflow valve 24 and the second overflow valve 26 are respectively connected with an oil tank, so that the pressure of the control cavity of the second cartridge valve 23 can be limited, and the safety of the system is protected.
The operation of the hydraulic control circuit of the present invention will be described on the basis of the above preferred embodiment. The hydraulic control circuit according to the present invention is applied to a construction machine having a telescopic boom, and will be described by taking a truck crane as an example.
In a standby state, the engine drives the hydraulic pump 4 to provide hydraulic oil, the main valve 34 is in a neutral position, an oil path between the hydraulic pump 4 and the hydraulic oil cylinder 5 is disconnected, the pressure of high-pressure oil generated by the hydraulic pump 4 exceeds the set pressure of the constant differential pressure valve 33, enters the operating valve oil return path 32 through the constant differential pressure valve 33, and flows back to an oil tank through the back pressure valve 36;
in the process of extending the telescopic arm, the engine drives the hydraulic pump 4 to provide hydraulic oil, the main valve 34 is reversed, so that the hydraulic oil sequentially passes through the main valve 34, the flow compensation valve 35, the second oil port C4 of the control valve 3 and the balance valve 6 to enter a rodless cavity of the hydraulic oil cylinder 5, the hydraulic oil in the rod cavity of the hydraulic oil cylinder 5 flows to the third cartridge valve 27 through the second working oil port of the control valve unit, at this time, the electromagnetic directional valve 28 is powered on, so that the second main oil port a2 and the first main oil port a1 of the third cartridge valve 27 are in a conducting state, the hydraulic oil sequentially flows back to the oil tank through the third cartridge valve 27 and the main valve 34, and the extending action of the telescopic arm is completed;
in the retracting process of the telescopic arm, the engine drives the hydraulic pump 4 to provide hydraulic oil, the main valve 34 is switched, at this time, the electromagnetic directional valve 28 is powered, so that the first main oil port a1 and the second main oil port a2 of the third cartridge valve 27 are in a conducting state, the hydraulic oil sequentially enters the rod cavity of the hydraulic oil cylinder 5 through the main valve 34, the flow compensation valve 35, the first oil port C3 of the control valve 3 and the third cartridge valve 27, and when the hydraulic oil flows through the control end of the balance valve 6, the balance valve 6 is opened through the control end of the balance valve 6, so that the hydraulic oil in the rod-free cavity of the hydraulic oil cylinder 5 sequentially flows back to the oil tank through the balance valve 6 and the main valve 34, and the retracting action of the telescopic arm is;
the hydraulic pump 4 continuously provides hydraulic oil to enable the piston and the cylinder bottom of the hydraulic oil cylinder 5 to be in a mechanical limit state of close contact; then, the pressure at the second working oil port P2 of the control valve unit is greater than the pressure in the control cavity of the first cartridge valve 21 set by the pressure reducing valve 22, the valve core of the first cartridge valve 21 is opened, so that hydraulic oil enters the energy accumulator 13, when the second working oil port P2 of the control valve unit reaches a certain pressure, the pressure at the second working oil port P2 of the control valve unit is greater than the pressure in the control cavity of the second cartridge valve 23 set by the first overflow valve 24, the first overflow valve 24 is opened, hydraulic oil can flow back to the oil tank through the first overflow valve 24, at this time, the pressure in the rod cavity of the hydraulic oil cylinder 5 is the pressure to be maintained in the driving state, and the pressure in the rod cavity of the hydraulic oil cylinder 5 in the driving state is individually adjustable; then, the pilot oil path switching valve 25 is controlled to change the direction, so that the second overflow valve 26 is connected with the control cavity of the second cartridge valve 23 through the pilot oil path switching valve 25 to limit the pressure of the control cavity of the second cartridge valve 23, and since the pressure set by the second overflow valve 26 is greater than the pressure set by the first overflow valve 24, the hydraulic oil does not flow back to the oil tank any more; then, the electromagnetic directional valve 28 is de-energized, and the control valve working pipeline 11 is cut off, so that the first main oil port a1 of the third cartridge valve 27 is not communicated with the second main oil port a2 thereof, and the arrangement is such that the pressure control on the rod cavity of the hydraulic oil cylinder 5 can be ensured; and then the lifting telescopic boom is placed on the boom support through the amplitude variation oil cylinder.
In the process of driving, the telescopic arm and the lower vehicle of the automobile crane have the same initial speed, when emergency braking occurs, the telescopic arm has certain inertia, and in the process of kinetic energy release, the telescopic arm has the tendency of driving a cylinder sleeve of the hydraulic oil cylinder 5 to move, and due to the action of the first cartridge valve (21) and the second cartridge valve (23), the hydraulic oil cylinder 5 has the effect of hindering the telescopic arm from extending, so that the inertia force is overcome, and the telescopic arm is prevented from extending, wherein due to the fact that the control valve unit adopts the cartridge valve group, the problem of leakage of the main valve 34 is solved, the pressure maintaining performance of a rod cavity of the hydraulic oil cylinder 5 is guaranteed, and the problem of extension of a suspension arm in the process of driving braking can be effectively overcome.
According to the technical scheme, the problem that the suspension arm stretches out when the automobile crane is braked is solved on the premise that the existing telescopic performance is not reduced, and the automobile crane is particularly suitable for automobile cranes with medium and small tonnages; the operation is relatively simple, and the running safety and reliability of the crane are effectively improved.
It should be noted that the hydraulic control circuit of the present invention is not limited to the truck crane, and can also be applied to other engineering equipment with a telescopic boom, such as an excavator.
The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, numerous simple modifications can be made to the technical solution of the invention, including combinations of the individual specific technical features in any suitable way. The invention is not described in detail in order to avoid unnecessary repetition. Such simple modifications and combinations should be considered within the scope of the present disclosure as well.
Claims (11)
1. A control valve unit is characterized by comprising a control valve working pipeline (11) for connecting a first working oil port (P1) and a second working oil port (P2), a direction control valve, a first pressure control valve, a second pressure control valve and a control valve oil return pipeline (12) which are arranged on the control valve working pipeline (11); the first pressure control valve is located on the oil circuit between second work hydraulic fluid port (P2) and energy storage ware (13), energy storage ware (13) with still install between second work hydraulic fluid port (P2) and mend oily check valve (14), so as to make hydraulic oil folk prescription in energy storage ware (13) is to the flow direction second work hydraulic fluid port (P2), the second pressure control valve is located second work hydraulic fluid port (P2) with the oil circuit between control valve oil return line (12) is gone up.
2. The control valve unit according to claim 1, characterized in that the first pressure control valve comprises a first cartridge valve (21) and a pressure reducing valve (22), the pressure reducing valve (22) being mounted on an oil path between a control chamber of the first cartridge valve (21) and the accumulator (13); the energy accumulator (13) is connected with the second working fluid port (P2) through the first cartridge valve (21).
3. The control valve unit according to claim 1, characterized in that the second pressure control valve comprises a second cartridge valve (23) and a first overflow valve (24), the control chamber of the second cartridge valve (23) being connected to the control valve return line (12) via the first overflow valve (24), and the second working port (P2) being connected to the control valve return line (12) via the second cartridge valve (23).
4. The control valve unit according to claim 3, characterized in that the second pressure control valve further comprises a pilot oil path switching valve (25) and a second overflow valve (26) connected to the control valve return line (12), the first and second overflow valves (24, 26) being connected to the control chamber of the second cartridge valve (23) through the pilot oil path switching valve (25), the control chamber of the second cartridge valve (23) being selectively communicable with the first overflow valve (24) or the second overflow valve (26) through the pilot oil path switching valve (25).
5. The control valve unit according to any one of claims 1 to 4, wherein the directional control valve comprises a third cartridge valve (27) and a solenoid directional valve (28), the third cartridge valve (27) comprises a first main port (A1) connected with the first working port (P1), a second main port (A2) connected with the second working port (P2) and a control cavity connected with the first port (B1) of the solenoid directional valve (28), and the solenoid directional valve (28) comprises the first port (B1), a second port (B2) connected with the second main port (A2) of the third cartridge valve (27) and a third port (B3) connected with the control valve return line (12) so as to control the on-off of the third cartridge valve (27).
6. The control valve unit according to any one of claims 1 to 4, characterized in that the directional control valve is an oil passage cut-off valve.
7. The control valve unit according to claim 6, wherein the oil passage on-off valve is a two-position two-way valve to enable control of on-off of the control valve working line (11).
8. A hydraulic control circuit, characterized by comprising a control valve unit according to any one of claims 1 to 7, a pilot valve (3) and a hydraulic pump (4) connected to the pilot valve (3), the pilot valve (3) being connected to the rod chamber of a hydraulic ram (5) through the control valve unit, and the pilot valve (3) being connected to the rodless chamber of the hydraulic ram (5) through a balance valve (6), the control end of the balance valve (6) being connected to the rod chamber of the hydraulic ram (5).
9. The hydraulic control circuit according to claim 8, wherein the pilot valve (3) includes a pilot valve oil inlet passage (31), a pilot valve oil return passage (32), an oil inlet (C1) connected to the pilot valve oil inlet passage (31), an oil return port (C2) connected to the pilot valve oil return passage (32), a first oil port (C3) connected to the control valve unit, a second oil port (C4) connected to the balancing valve (6), a differential pressure valve (33), and a main valve (34) located between the pilot valve oil inlet passage (31) and the pilot valve oil return passage (32), the differential pressure valve (33) is located on the oil passage between the pilot valve oil inlet passage (31) and the pilot valve oil return passage (32), the main valve (34) is connected to the first oil port (C3) and the second oil port (C4) of the pilot valve (3) through a flow compensating valve (35), respectively, the hydraulic pump (4) is connected with an oil inlet (C1) of the operating valve (3).
10. The hydraulic control circuit according to claim 9, wherein a back pressure valve (36) is provided on the pilot valve oil return path (32), a main overflow valve (37) is further provided between the pilot valve oil inlet path (31) and the pilot valve oil return path (32), and a secondary overflow valve (38) is provided between the second port (C4) of the pilot valve (3) and the pilot valve oil return path (32).
11. A working installation with a telescopic boom, characterized by comprising a hydraulic control circuit according to any one of claims 8-10.
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| CN202010991630.5A CN112173994B (en) | 2020-09-18 | 2020-09-18 | Control valve unit, hydraulic control loop and engineering equipment with telescopic crane boom |
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| CN202010991630.5A CN112173994B (en) | 2020-09-18 | 2020-09-18 | Control valve unit, hydraulic control loop and engineering equipment with telescopic crane boom |
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| CN112173994B CN112173994B (en) | 2021-11-05 |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113896121A (en) * | 2021-10-08 | 2022-01-07 | 徐州重型机械有限公司 | Crane bolt type telescopic system and crane |
| CN114412853A (en) * | 2021-12-31 | 2022-04-29 | 徐州重型机械有限公司 | Double-cylinder-head telescopic system and control method |
| CN114412853B (en) * | 2021-12-31 | 2024-05-14 | 徐州重型机械有限公司 | Double-cylinder head telescopic system and control method |
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| EP0460475A1 (en) * | 1990-06-07 | 1991-12-11 | Krupp Industrietechnik Gmbh | Telescopic jib with coupling device for extension mechanism |
| CN106065883A (en) * | 2016-08-19 | 2016-11-02 | 三汽车起重机械有限公司 | Stop valve, crane arm telescopic hydraulic system and crane |
| CN111197602A (en) * | 2020-01-14 | 2020-05-26 | 宝鸡石油机械有限责任公司 | Seabed base plate hydraulic system and energy-saving control method of system |
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2020
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0460475A1 (en) * | 1990-06-07 | 1991-12-11 | Krupp Industrietechnik Gmbh | Telescopic jib with coupling device for extension mechanism |
| CN106065883A (en) * | 2016-08-19 | 2016-11-02 | 三汽车起重机械有限公司 | Stop valve, crane arm telescopic hydraulic system and crane |
| CN111197602A (en) * | 2020-01-14 | 2020-05-26 | 宝鸡石油机械有限责任公司 | Seabed base plate hydraulic system and energy-saving control method of system |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113896121A (en) * | 2021-10-08 | 2022-01-07 | 徐州重型机械有限公司 | Crane bolt type telescopic system and crane |
| CN114412853A (en) * | 2021-12-31 | 2022-04-29 | 徐州重型机械有限公司 | Double-cylinder-head telescopic system and control method |
| CN114412853B (en) * | 2021-12-31 | 2024-05-14 | 徐州重型机械有限公司 | Double-cylinder head telescopic system and control method |
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| CN112173994B (en) | 2021-11-05 |
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