CN104692266A - Hydraulic system for telescopic buffer of crane boom and crane - Google Patents
Hydraulic system for telescopic buffer of crane boom and crane Download PDFInfo
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- CN104692266A CN104692266A CN201510061037.XA CN201510061037A CN104692266A CN 104692266 A CN104692266 A CN 104692266A CN 201510061037 A CN201510061037 A CN 201510061037A CN 104692266 A CN104692266 A CN 104692266A
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- Prior art keywords
- valve
- oil
- hydraulic system
- telescopic
- crane arm
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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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- 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
- F15B13/0401—Valve members; Fluid interconnections therefor
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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
- F15B13/0401—Valve members; Fluid interconnections therefor
- F15B13/0407—Means for damping the valve member movement
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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
- F15B15/22—Other details, e.g. assembly with regulating devices for accelerating or decelerating the stroke
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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
- F15B20/00—Safety arrangements for fluid actuator systems; Applications of safety devices in fluid actuator systems; Emergency measures for fluid actuator systems
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- General Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Fluid-Pressure Circuits (AREA)
Abstract
The invention discloses a hydraulic system for telescopic buffer of a crane boom and a crane. The hydraulic system for telescopic buffer of the crane boom comprises a telescopic oil cylinder, a main valve and a balance valve, wherein a first working oil port and a second working oil port of the main valve are respectively connected to a rod chamber of the telescopic oil cylinder and a free oil inlet of the balance valve in a communication way, a free oil outlet of the balance valve is connected to a rodless chamber of the telescopic oil cylinder in a communication way, and the first working oil port is also connected to a control oil port of the balance valve in a communication way through a control oil line; and the hydraulic system for telescopic buffer of the crane boom also comprises an auxiliary pressure-relief oil line, a through flow damper and a hydraulic control pressure-relief on-off valve, wherein the oil inlet end of the auxiliary pressure-relief oil line is connected to the rodless chamber of the telescopic oil cylinder in a communication way, the through flow damper and the hydraulic control pressure-relief on-off valve are arranged on the auxiliary pressure-relief oil line, and the control oil port of the hydraulic control pressure-relief on-off valve is connected to the control oil line or the first working oil port in a communication way. By implementing the hydraulic system, impact generated by the balance valve or a pressure shunting damper when the crane boom is started to be shrunk can be effectively reduced.
Description
Technical field
The present invention relates to crane arm technical field of hydraulic, particularly crane arm stretches buffer hydraulic system and hoisting crane.
Background technology
A kind of crane arm (abbreviation single-cylinder pin-type erector arm of crane) with single telescopic oil cylinder has been there is in recent years in crane field, this crane arm comprise basic arm and successively telescopically be arranged at the multi-stage telescopic arms in this basic arm, the piston rod of this telescopic oil cylinder is connected to basic arm, cylinder barrel is provided with cylinder head, the both sides of cylinder head are provided with two corresponding cylinder pins, the center shaft of these two cylinder pins and the center shaft of described telescopic oil cylinder coplanar, the cylinder barrel of this telescopic oil cylinder can optionally lock or discharge the relative position of itself and arbitrary joint telescopic boom when above-mentioned cylinder pin stretches out or regains.In addition, between adjacent each joint telescopic boom and be equipped with arm pin between basic arm and first segment telescopic boom, the relative positions between adjacent two joint telescopic booms and between basic arm and first segment telescopic boom optionally lock by this arm pin or discharge.
First the cylinder barrel of this telescopic oil cylinder can be locked by cylinder pin and minor details telescopic boom, minor details telescopic boom and joint telescopic boom second from the bottom is discharged by retraction arm pin simultaneously, and now minor details telescopic boom can be taken out of by extend action by the cylinder barrel of this telescopic oil cylinder; After minor details telescopic boom arrives desired location, itself and joint telescopic boom second from the bottom are relocked, regain the cylinder barrel of telescopic oil cylinder and itself and joint telescopic boom second from the bottom are locked, then joint telescopic boom second from the bottom and joint telescopic boom third from the bottom are discharged, now joint telescopic boom second from the bottom can be taken out of by the cylinder barrel of telescopic oil cylinder, can realize stretching out successively of each joint telescopic boom by that analogy.
In such scheme, the Plug Action of cylinder pin and arm pin is generally controlled respectively by the cylinder pin oil cylinder fixed with cylinder barrel and arm pin oil cylinder, because cylinder pin oil cylinder and arm pin oil cylinder are all in telescopic boom, and fix with telescopic oil cylinder, move forward and backward along with the action of cylinder barrel, the pipeline of cylinder pin oil cylinder and the external pressure oil-source of arm pin oil cylinder is difficult to arrange.
At present, in order to address this problem, usually the vibrational power flow of telescopic oil cylinder is become situation as shown in Figure 1, as shown in Figure 1, this telescopic oil cylinder 3 comprises cylinder barrel 31, piston rod 32, piston 33 and core pipe 34; The first oil pocket 325, second oil pocket 326 and the 3rd oil pocket 327 is offered in piston rod 32; The external part of piston rod 32 offer be communicated in the first oil pocket 325 the first hydraulic fluid port 321, be communicated in the second hydraulic fluid port 322 of the second oil pocket 326 and be communicated in the 3rd hydraulic fluid port 323 of the 3rd oil pocket 327; The sidewall of the first oil pocket 325 adjacent piston 33 offers the 4th hydraulic fluid port the 324, four hydraulic fluid port 324 and be communicated with rod chamber 311 and the first oil pocket 325; Piston 33 runs through and is provided with mounting hole 331 and the 5th hydraulic fluid port 332, mounting hole 331 is communicated with the second oil pocket 326 and rodless cavity the 312, five hydraulic fluid port 332 is communicated with the 3rd oil pocket 327 and rodless cavity 312; Core pipe 34 is arranged in mounting hole 331 movably, and its one end is positioned at the second oil pocket 326, and another is fixed on cylinder barrel 31 terminal interior surface through rodless cavity 312, and the end opens of cylinder barrel 31 has the core pipe oil-feed port 313 be communicated with core pipe 34.By the main valve (main reversing valve) of hydraulic efficiency pressure system to the first hydraulic fluid port 321 fuel feeding, from the 3rd hydraulic fluid port 323 oil return, or to the 3rd hydraulic fluid port 323 oil-feed, the first hydraulic fluid port 321 oil return, the withdrawal action of telescopic oil cylinder can be realized or stretch out work (normal fore and aft motion); And by main valve to the second hydraulic fluid port 322 fuel feeding, can realize by core pipe oil-feed port 313 to cylinder pin oil cylinder or arm pin oil cylinder fuel feeding, effectively can simplify the layout of cylinder pin oil cylinder and arm pin oil cylinder hydraulic pipeline like this.
Be in the Chinese patent literature of CN103420290A at publication number, give a kind of crane arm telescopic hydraulic system adopting above-mentioned telescopic oil cylinder, shown in composition graphs 2, this hydraulic efficiency pressure system comprises main valve 1, balance cock 2, telescopic oil cylinder 3, cylinder pin oil cylinder 4, arm pin oil cylinder 5 and ball valve 6 etc., wherein, first actuator port A and the second actuator port B of main valve 1 can be connected to the first hydraulic fluid port 321 (keeping being communicated with the rod chamber 311 of telescopic oil cylinder 3) of telescopic oil cylinder 3 and the free oil inlet of balance cock 2 respectively communicatively, the free oil outlet of balance cock 2 can be connected to the 3rd hydraulic fluid port 323 (keeping being communicated with the rodless cavity 312 of telescopic oil cylinder 3) of telescopic oil cylinder 3 communicatively, the control port of balance cock 2 is connected to the first actuator port A of main valve 1 by oil circuit control 200, second hydraulic fluid port 322 of telescopic oil cylinder 3 (under the control of ball valve 6 by core pipe 34 to cylinder pin oil cylinder 4 or arm pin oil cylinder 5 fuel feeding) by the external oil sources of oil feeding line 100.
In the course of the work, if need control cylinder pin oil cylinder 4 or the action of arm pin oil cylinder 5, can telescopic oil cylinder 3 stop flexible after, by oil feeding line 100 through core pipe 34, ball valve 6 pairs of cylinder pin oil cylinders 4 or arm pin oil cylinder 5 fuel feeding, if desired control crane arm (telescopic oil cylinder 3) to stretch out, can after cylinder pin oil cylinder 4 or arm pin oil cylinder 5 stop action, control bound 1 is in left position, by the oil inlet P supply pressure oil of oil sources (as oil pump) to main valve 1, the second actuator port B of such pressure oil through main valve 1, the rodless cavity of balance cock 2 (check valve 21) arrival telescopic oil cylinder 3, the rod chamber oil return of telescopic oil cylinder 3 is got back to fuel tank by through the first actuator port A of main valve 1, oil return inlet T, thus is realized stretching out of telescopic oil cylinder 3, if crane arm (telescopic oil cylinder 3) need be controlled retract, right position can be in by control bound 1, pressure oil arrives the rod chamber of telescopic oil cylinder 3 after the first actuator port A of main valve 1, and pressure oil also acts on balance cock 2 control port by oil circuit control 200 is in reverse connected state (even if the order spool 22 in balance cock 2 is in connected state) to make balance cock 2, the oil return of the rodless cavity of such telescopic oil cylinder 3 namely by balance cock 2 order spool 22 and through the second actuator port B of main valve 1, oil return inlet T gets back to fuel tank, thus realize the retraction of telescopic oil cylinder 3.
Adopt the single-cylinder pin-type erector arm of crane of aforementioned schemes owing to being subject to joint arm working accuracy, assembly clearance, the impact of the many factors such as telescopic hydraulic system, greater impact is there will be when expanding-contracting action start and stop, between this impact and various factors specifically contact or one-to-one relationship is difficult to determine completely, current normal method realizes break-in between arm by continuous crane arm expanding-contracting action in debug process, suitably to reduce the impact that flexible start and stop produce, in addition, in order to improve the stability of telescopic oil cylinder start-stop, generally in balance cock 2, between control port and free oil inlet, be provided with dividing potential drop damping 23, but present inventor is realizing finding in process of the present invention:
This dividing potential drop damping 23 1 aspect can realize carrying out filtering to the oil pressure of control port, guarantee order spool 22 stable movement in Dynamic Regulating Process of balance cock 2, on the other hand, dividing potential drop damping 23 of a size suitable can affect the delay time that balance cock 2 (order spool 22) is opened, therefore dividing potential drop damping 23 exist necessary.But carry out in the process of contracting arm action test at single-cylinder pin-type erector arm of crane, contriver finds when carrying out rodless cavity pressure test to telescopic oil cylinder 3, when crane arm contracting arm and telescopic oil cylinder 3 retract action start, the instantaneous generation of rodless cavity 312 of telescopic oil cylinder 3 builds the pressure phenomenon, and pressure is larger, when balance cock 2 delayed start-up, pressure abrupt release after balance cock 2 is opened of rodless cavity 312, larger impact can be produced, external manifestation is that crane arm produces corresponding impact when contracting arm starts, thus affects the stability of expanding-contracting action.Contriver determines in total impact that crane arm produces when contracting arm starts thus, and some impacts because balance cock 2 or dividing potential drop damping 23 cause, and after quantizing, can also show that this part impacts the cardinal principle accounting in total impact.Further, contriver finds after in-depth analysis, the reason producing above-mentioned phenomenon is, the telescopic oil cylinder 3 of single-cylinder pin-type erector arm of crane is when contracting arm starts, the high pressure oil of its rod chamber 311 builds pressure rapidly, and the fluid of rodless cavity 312 must carry out oil return by the order spool 22 of balance cock 2, but the existence of dividing potential drop damping 23 makes the unlatching of the order spool 22 of balance cock 2 occur delay phenomenon, thus cause rodless cavity 312 to build the pressure rapidly, when the order spool 22 of balance cock 2 is opened, generation is impacted by the pressure abrupt release of rodless cavity 312, thus affect crane arm stability when contracting arm starts.
Therefore, after present inventor finds above-mentioned phenomenon, how effectively reducing the impact that crane arm produces because of balance cock 2 or dividing potential drop damping 23 when contracting arm starts, is the direction of contriver's effort always.
Summary of the invention
In view of this, an object of the present invention is to provide a kind of crane arm to stretch buffer hydraulic system, effectively to reduce the impact that crane arm produces because of balance cock or dividing potential drop damping when contracting arm starts, thus improves the stability of crane arm.
Specifically, this crane arm buffer hydraulic system of stretching comprises telescopic oil cylinder, main valve and balance cock, first actuator port of described main valve and the second actuator port can be connected to the rod chamber of described telescopic oil cylinder and the free oil inlet of described balance cock respectively communicatively, the free oil outlet of described balance cock can be connected to the rodless cavity of described telescopic oil cylinder communicatively, and described first actuator port also can be connected to the control port of described balance cock communicatively by oil circuit control; Described crane arm buffer hydraulic system of stretching also comprises auxiliary pressure release oil circuit, through-flow damping and liquid control pressure releasing on-off valve, the oil inlet end of described auxiliary oil drainage oil circuit can be connected to the rodless cavity of described telescopic oil cylinder communicatively, described through-flow damping and described liquid control pressure releasing on-off valve are arranged on described auxiliary pressure release oil circuit, and the control port of described liquid control pressure releasing on-off valve can be connected to described oil circuit control or described first actuator port communicatively.
Further, described liquid control pressure releasing on-off valve is hydraulic control one-way valve, and described through-flow damping is dash pot valve or by pass valve.
Further, described through-flow damping and described liquid control pressure releasing on-off valve are integrated in same valve block or are integrated in described balance cock.
Further, the oil outlet end of described auxiliary pressure release oil circuit can be connected to fuel tank or described second actuator port communicatively.
Further, the oil outlet end of the contiguous described auxiliary pressure release oil circuit of described through-flow damping is arranged, and the oil inlet end of the contiguous described auxiliary hydraulic pressure oil circuit of described liquid control pressure releasing on-off valve is arranged.
Further, described crane arm buffer hydraulic system of stretching also comprises the control cock of the on off mode for controlling the oil circuit between described first actuator port and described rod chamber.
Further, described control cock comprises inserted valve and change-over valve, the end face hydraulic fluid port of described inserted valve can be connected to described first actuator port communicatively, the anchor ring hydraulic fluid port of described inserted valve can be connected to described rod chamber communicatively, and the spring cavity hydraulic fluid port of described inserted valve is optionally communicated in by described change-over valve and controls oil sources or fuel tank.
Further, described control cock also comprises flow regulating valve, and described flow regulating valve is arranged on the oil circuit between the spring cavity hydraulic fluid port of described inserted valve and described change-over valve.
Further, described control cock also comprises the first by pass valve and the second by pass valve; The oil inlet of described first by pass valve is connected to the anchor ring hydraulic fluid port of described inserted valve, and outgate is connected to described first actuator port or fuel tank; The oil inlet of described second by pass valve is connected on the oil circuit between the spring cavity hydraulic fluid port of described inserted valve and described change-over valve, and outgate is connected to fuel tank or described first actuator port.
Another object of the present invention is to provide a kind of hoisting crane, to improve stability and the safety performance of this hoisting crane.
Specifically, this hoisting crane crane arm be provided with described in above-mentioned any one stretches buffer hydraulic system.
Implement crane arm of the present invention to stretch buffer hydraulic system, when crane arm contracting arm startup and telescopic oil cylinder retract action start, pressure oil arrives the rod chamber of telescopic oil cylinder through main valve first actuator port, the rod chamber of telescopic oil cylinder is made to build pressure rapidly, while rod chamber builds pressure, pressure oil also leads to the control port of balance cock and the control port of liquid control pressure releasing on-off valve by oil circuit control, owing to there is dividing potential drop damping in balance cock, thus liquid control pressure releasing on-off valve is opened under the effect of pressure oil early than balance cock, the rodless cavity fluid of such telescopic oil cylinder can first realize stablizing pressure release by the auxiliary hydraulic pressure oil circuit being provided with liquid control pressure releasing on-off valve and through-flow damping, avoid telescopic oil cylinder rodless cavity when contracting arm starts and occur the phenomenon that builds the pressure, and then balance cock is oppositely opened by pressure oil, guarantee that flexible rodless cavity fluid can be smooth, in time by balance cock oil return, whole process effectively prevent the probability producing greater impact, therefore compared with prior art, the present invention effectively reduces crane arm when contracting arm starts because of impact that balance cock or dividing potential drop damping produce, thus decrease total impact of crane arm generation, improve the stability of crane arm.
Accompanying drawing explanation
The accompanying drawing forming a part of the present invention is used to provide a further understanding of the present invention, and schematic description and description of the present invention, for explaining the present invention, does not form inappropriate limitation of the present invention.In the accompanying drawings:
Fig. 1 is the structural representation of existing a kind of telescopic oil cylinder;
Fig. 2 is the principle schematic of a kind of typical crane arm telescopic hydraulic system in prior art;
Fig. 3 is that the crane arm of the embodiment of the present invention one stretches the principle schematic of buffer hydraulic system;
Fig. 4 is that the crane arm of the embodiment of the present invention two stretches the principle schematic of buffer hydraulic system;
Fig. 5 is that the crane arm of the embodiment of the present invention three stretches the principle schematic of buffer hydraulic system;
Fig. 6 is that the crane arm of the embodiment of the present invention four stretches the principle schematic of buffer hydraulic system;
Fig. 7 is that the crane arm of the embodiment of the present invention five stretches the principle schematic of buffer hydraulic system.
Main element nomenclature:
1 main valve
2 balance cocks
3 telescopic oil cylinders
4 cylinder pin oil cylinders
5 arm pin oil cylinders
6 ball valves
7 control cock
8 valve blocks
21 check valves
22 order spools
23 dividing potential drop dampings
71 inserted valves
72 flow regulating valve
73 change-over valves
74 first by pass valves
75 second by pass valves
81 liquid control pressure releasing on-off valves
82 through-flow dampings
100 oil feeding lines
200 oil circuit controls
300 auxiliary pressure release oil circuits
Detailed description of the invention
To it should be pointed out that in this part to the description of concrete structure and description order it is only explanation to specific embodiment, should not be considered as there is any restriction to protection scope of the present invention.In addition, when not conflicting, the embodiment in this part and the feature in embodiment can combine mutually.
Please refer to Fig. 1 to Fig. 6, below in conjunction with accompanying drawing, various embodiments of the present invention are elaborated.
Shown in composition graphs 1 and Fig. 3, the crane arm of the embodiment of the present invention one buffer hydraulic system of stretching can comprise main valve 1, balance cock 2, telescopic oil cylinder 3, cylinder pin oil cylinder 4, arm pin oil cylinder 5, ball valve 6, auxiliary pressure release oil circuit 300, liquid control pressure releasing on-off valve 81 and through-flow damping 82.
Wherein, concrete structure and the telescopic oil cylinder 3 of telescopic oil cylinder 3 can see the descriptions of background technology part with the relation of cylinder pin oil cylinder 4, arm pin oil cylinder 5, ball valve 6 and oil feeding line 100, structure and the effect of check valve 21, sequentially spool 22 and dividing potential drop damping 23 in balance cock 2 also see the description of background technology part, no longer can launch at this.
First actuator port A of main valve 1 and the second actuator port B can be connected to the first hydraulic fluid port 321 (the first hydraulic fluid port 321 is communicated in rod chamber 311 by the first oil pocket 325 and the 4th hydraulic fluid port 324) of telescopic oil cylinder 3 and the free oil inlet of balance cock 2 respectively communicatively, the free oil outlet of balance cock 2 can be connected to the 3rd hydraulic fluid port 323 (the 3rd hydraulic fluid port 323 is communicated in rodless cavity 312 by the 3rd oil pocket 327 and the 5th hydraulic fluid port 332) of telescopic oil cylinder 3 communicatively, and the control port of balance cock 2 and the control port of liquid control pressure releasing on-off valve 81 all can be connected on the oil circuit between main valve 1 first actuator port A and telescopic oil cylinder 3 first hydraulic fluid port 321 communicatively by oil circuit control 200.
Through-flow damping 82 and liquid control pressure releasing on-off valve 81 are arranged on auxiliary pressure release oil circuit 300 respectively, the oil inlet end of auxiliary oil drainage oil circuit 300 can be connected to the 3rd hydraulic fluid port 323 (can be connected to rodless cavity 312 communicatively) of telescopic oil cylinder 3 communicatively or be connected to the free oil outlet of balance cock 2, oil outlet end is connected to fuel tank, and the initial condition of liquid control pressure releasing on-off valve 81 is off state; As shown in Figure 3, when specifically implementing, as a kind of optimal way, the oil outlet end that through-flow damping 82 can be close to auxiliary oil drainage oil circuit 300 is arranged, and the oil inlet end that liquid control pressure releasing on-off valve 81 can be close to auxiliary pressure release oil circuit 300 is arranged.
In use, the oil inlet P of main valve 1 can external oil sources (as oil pump), oil return inlet T can be connected to fuel tank, and main valve 1 can adopt three-position four-way valve, for the main valve shown in Fig. 3, the principle of work of the embodiment of the present invention one and corresponding technique effect is described below:
In the course of the work, if need control cylinder pin oil cylinder 4 or the action of arm pin oil cylinder 5, can stop flexible rear (when main valve 1 is in meta), by the one fuel feeding of oil feeding line 100 in core pipe 34, core pipe oil-feed port 313, ball valve 6 pairs of cylinder pin oil cylinders 4 and arm pin oil cylinder 5 at telescopic oil cylinder 3.If desired control crane arm (telescopic oil cylinder 3) to stretch out, can after cylinder pin oil cylinder 4 or arm pin oil cylinder 5 stop action, control bound 1 is in left position, by the oil inlet P supply pressure oil of oil sources to main valve 1, such pressure oil is through the second actuator port B of main valve 1, after balance cock 2 and through the 3rd hydraulic fluid port 323 of telescopic oil cylinder 3, 5th hydraulic fluid port arrives the rodless cavity 312 of telescopic oil cylinder 3, rodless cavity 312 is made to build pressure rapidly, fluid in the rod chamber 311 of meanwhile telescopic oil cylinder 3 is through its 4th hydraulic fluid port 324, first oil pocket 325, the first actuator port A again through main valve 1 after first hydraulic fluid port 321, oil return inlet T oil return, thus realize stretching out of telescopic oil cylinder 3.
If crane arm (telescopic oil cylinder 3) contracting arm need be controlled, right position can be in by control bound 1, now pressure oil arrives the rod chamber 312 of telescopic oil cylinder 3 through main valve 1 first actuator port A, the rod chamber 312 of telescopic oil cylinder 3 is made to build pressure rapidly, while rod chamber 312 builds pressure, pressure oil (its pressure and rod chamber 312, the oil pressure of the first actuator port A keeps unanimous on the whole) also lead to the control port of balance cock 2 and the control port of liquid control pressure releasing on-off valve 81 by oil circuit control 200, owing to there is dividing potential drop damping 23 in balance cock 2, thus liquid control pressure releasing on-off valve 81 is opened under the effect of pressure oil early than balance cock 2, rodless cavity 312 fluid of such telescopic oil cylinder 3 can first realize stablizing pressure release by the auxiliary hydraulic pressure oil circuit 300 being provided with liquid control pressure releasing on-off valve 81 and through-flow damping 82, the rodless cavity 312 of crane arm telescopic oil cylinder 3 when contracting arm starts is avoided to occur the phenomenon that builds the pressure, and then balance cock is oppositely opened by (in the schedule time) pressure oil, ensure that flexible rodless cavity 312 fluid can be smooth, in time by balance cock 2 oil return, the probability occurring greater impact can be effectively reduced in whole process, therefore compared with prior art, the embodiment of the present invention one effectively can reduce crane arm when contracting arm starts because of impact that balance cock 2 or dividing potential drop damping 23 produce, thus decrease total impact that crane arm produces when action, improve the stability of crane arm.
It should be noted that, in specific implementation process, through-flow damping 82 and the liquid control pressure releasing on-off valve 81 of appropriate size can be selected, make auxiliary pressure release oil circuit 300 can stablize pressure release for the rodless cavity 312 of telescopic oil cylinder 3, and the liquid control pressure releasing on-off valve 81 of this specification can ensure that the amount of leakage of the rodless cavity 312 of telescopic oil cylinder 3 is zero (close to zero) at telescopic oil cylinder 3 when static or when band carries flexible together with balance cock 2, and the opening time difference that can make liquid control pressure releasing on-off valve 81 and balance cock 2 order spool 22 is predetermined value, thus guarantee that liquid control pressure releasing on-off valve 81 preferential balance cock 2 when contracting arm starts is opened.
In addition, in this application, " off-state " of liquid control pressure releasing on-off valve 81 refers to that the rodless cavity 312 of telescopic oil cylinder 3 or the pressure oil at the free oil outlet place of balance cock 2 can not realize pressure release through the liquid control pressure releasing on-off valve 81 of auxiliary pressure release oil circuit 300, namely oil inlet end to the circulating direction of oil outlet end of auxiliary pressure release oil circuit 300 is in off condition, and whether oil outlet end to the circulating direction of oil inlet end as auxiliary pressure release oil circuit 300 is in off condition and unrestricted.Such as, as shown in Figure 3, as a kind of preferred exemplary, in embodiment one, liquid control pressure releasing on-off valve 81 can adopt hydraulic control one-way valve, and through-flow damping 82 can adopt dash pot valve; More preferably, as shown in Figure 3, liquid control pressure releasing on-off valve 81 and through-flow damping 82 can be integrated in same valve block 8, so that install and arrange.
Certainly, in other embodiments, be not limited to aforementioned preferred situation, such as, shown in composition graphs 4, in embodiment two, also can through-flow damping 82 (not shown) be integrated in liquid control pressure releasing on-off valve 81 (being specially hydraulic control one-way valve), correspondingly, this liquid control pressure releasing on-off valve 81 also can form valve block 8, so that install and arrange.And for example, shown in composition graphs 5, in embodiment three, through-flow damping 82 adopts (low pressure) by pass valve, and liquid control pressure releasing on-off valve 81 adopts hydraulic control one-way valve; Damping that this is through-flow 82 and this liquid control pressure releasing on-off valve 81 also can be integrated in same valve block 8.
In aforementioned various embodiment, the oil outlet end of auxiliary pressure release oil circuit 300 is connected to fuel tank, but in other embodiments, be not limited to this, the oil outlet end of auxiliary pressure release oil circuit 300 also can be connected to the free oil inlet of balance cock 2 or the second actuator port of main valve 1, such as, shown in composition graphs 6, in embodiment four, adopt the through-flow damping 82 of dash pot valve, adopt the liquid control pressure releasing on-off valve 81 of hydraulic control one-way valve and auxiliary oil drainage oil circuit 300 can be integrated in balance cock 2, after adopting this scheme, if when the check valve 21 of balance cock 2 disconnects because of fault, the liquid control pressure releasing on-off valve 81 of hydraulic control one-way valve alternative check valve 2 of can also meeting an urgent need is adopted to realize stretch.And for example, shown in composition graphs 7, in embodiment five, adopt the through-flow damping 82 of by pass valve, adopt the liquid control pressure releasing on-off valve 81 of hydraulic control one-way valve and auxiliary oil drainage oil circuit 300 can be integrated in balance cock 2.
The explanation of embodiment two to embodiment five miscellaneous part and principle of work see the associated description of embodiment one, no longer can launch at this.It should be noted that, before in some embodiments, liquid control pressure releasing on-off valve 81 can adopt hydraulic control one-way valve, but in other embodiments, liquid control pressure releasing on-off valve 81 also can adopt hydraulic-controlled switch valve.
It should be noted that, the crane arm of aforementioned various embodiment buffer hydraulic system of stretching all adopts the telescopic oil cylinder 3 shown in Fig. 1, but in other embodiments, is not limited to this, also can adopt other forms of telescopic oil cylinder.Certainly, the aforementioned various embodiment of telescopic oil cylinder 1 shown in Fig. 1 is adopted to optimize further, be described shown in embodiment in the lump composition graphs 3 and Fig. 1 below: particularly, in the course of the work, if need oil cylinder 4 action of control cylinder pin or the action of arm pin oil cylinder 5, oil feeding line 100 is to telescopic oil cylinder supply pressure oil, pressure oil will be full of in its second oil pocket 326 and core pipe 34, this pressure oil will produce separated hydraulic action to core pipe 34 two ends, make the cylinder barrel 31 of telescopic oil cylinder and piston rod 32 that relative motion (passive stretch out motion) occur, which decrease the stability of crane arm, hoisting crane is made to there is potential safety hazard.
In order to overcome this deficiency, crane arm buffer hydraulic system of stretching can also comprise a control cock 7, and this control cock 7 is for the on off mode of the oil circuit between the first actuator port A of control bound 1 and telescopic oil cylinder 3; As a kind of optimal way, control cock 7 can comprise inserted valve 71 and change-over valve 73, the end face hydraulic fluid port of inserted valve 71 can be connected to the first actuator port A of main valve 1 communicatively, the anchor ring hydraulic fluid port of inserted valve 71 can be connected to the first hydraulic fluid port 321 (the first hydraulic fluid port 321 is communicated in rod chamber 312) of telescopic oil cylinder 3 communicatively, the spring cavity hydraulic fluid port of inserted valve 71 is optionally communicated in by change-over valve 73 and controls oil sources or fuel tank, during concrete enforcement, change-over valve 73 can adopt 2/2-way (electromagnetism) valve shown in Fig. 3.
After adopting this scheme, when telescopic oil cylinder 3 normally works, by controlling change-over valve 73, the spring cavity hydraulic fluid port of inserted valve 71 is made to be connected to fuel tank, and then make to be in connected state between the end face hydraulic fluid port of inserted valve 71 and anchor ring hydraulic fluid port, the normal flexible of telescopic oil cylinder 3 can be realized like this by control bound 1 oil inlet and oil return, when telescopic oil cylinder 3 does not work, by controlling change-over valve 73, the spring cavity hydraulic fluid port of inserted valve 71 is connected to and independently controls oil sources, and then make to be in dissengaged positions between the end face hydraulic fluid port of inserted valve 71 and anchor ring hydraulic fluid port, thus cut off the oil return of telescopic oil cylinder 3 rod chamber 311, the rod chamber 311 of telescopic oil cylinder 3 is made to produce certain oil pressure (back pressure), consequent application force can offset because of core pipe oil pressure produce stretch out application force, avoid that telescopic oil cylinder 3 is passive because of core pipe oil pressure to be stretched out, improve the controllability of telescopic oil cylinder 3 and the stability of crane arm.
On this basis, the oil circuit between inserted valve 71 and change-over valve 73 can also arrange flow regulating valve 72, to improve the stationarity that inserted valve 71 state switches, thus improve the stationarity of telescopic oil cylinder 3.In addition, the first by pass valve 74 and the second by pass valve 75 can also be adopted, the oil inlet of the first by pass valve 74 is connected to the anchor ring hydraulic fluid port of inserted valve 71, outgate is connected to the first actuator port A or fuel tank of main valve 1, the oil inlet of the second by pass valve 75 is connected on the oil circuit between the spring cavity hydraulic fluid port of inserted valve 71 and change-over valve 73, and outgate is connected to the first actuator port A of fuel tank or main valve 1; Can prevent like this inserted valve 71 because of anchor ring hydraulic fluid port or spring cavity hydraulic fluid port oil pressure excessive and damage, also can prevent change-over valve 73 from affecting service life because oil pressure is excessive.
Other embodiments of the invention additionally provide a kind of hoisting crane, this hoisting crane is provided with above-mentioned crane arm and stretches buffer hydraulic system, because above-mentioned crane arm buffer hydraulic system of stretching can reduce the impact that crane arm produces because of balance cock or dividing potential drop damping when contracting arm starts, therefore, this hoisting crane has better stability and safety performance, the specific implementation process of its appropriate section is similar to the above embodiments, the specific implementation process of other parts see the associated description of prior art, hereby can not repeat.
The foregoing is only preferred embodiment of the present invention, not in order to limit the present invention, within the spirit and principles in the present invention all, any amendment done, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.
Claims (10)
1. a crane arm stretches buffer hydraulic system, comprise telescopic oil cylinder, main valve and balance cock, first actuator port of described main valve and the second actuator port can be connected to the rod chamber of described telescopic oil cylinder and the free oil inlet of described balance cock respectively communicatively, the free oil outlet of described balance cock can be connected to the rodless cavity of described telescopic oil cylinder communicatively, described first actuator port also can be connected to the control port of described balance cock communicatively by oil circuit control, it is characterized in that:
Described crane arm buffer hydraulic system of stretching also comprises auxiliary pressure release oil circuit, through-flow damping and liquid control pressure releasing on-off valve, the oil inlet end of described auxiliary oil drainage oil circuit can be connected to the rodless cavity of described telescopic oil cylinder communicatively, described through-flow damping and described liquid control pressure releasing on-off valve are arranged on described auxiliary pressure release oil circuit, and the control port of described liquid control pressure releasing on-off valve can be connected to described oil circuit control or described first actuator port communicatively.
2. crane arm as claimed in claim 1 stretches buffer hydraulic system, and it is characterized in that: described liquid control pressure releasing on-off valve is hydraulic control one-way valve, described through-flow damping is dash pot valve or by pass valve.
3. crane arm as claimed in claim 2 stretches buffer hydraulic system, it is characterized in that: described through-flow damping and described liquid control pressure releasing on-off valve are integrated in same valve block or are integrated in described balance cock.
4. crane arm as claimed in claim 1 stretches buffer hydraulic system, it is characterized in that: the oil outlet end of described auxiliary pressure release oil circuit can be connected to fuel tank or described second actuator port communicatively.
5. crane arm as claimed in claim 4 stretches buffer hydraulic system, and it is characterized in that: the oil outlet end of the contiguous described auxiliary pressure release oil circuit of described through-flow damping is arranged, the oil inlet end of the contiguous described auxiliary hydraulic pressure oil circuit of described liquid control pressure releasing on-off valve is arranged.
6. the crane arm as described in any one of claim 1 to 5 stretches buffer hydraulic system, it is characterized in that: described crane arm buffer hydraulic system of stretching also comprises the control cock of the on off mode for controlling the oil circuit between described first actuator port and described rod chamber.
7. crane arm as claimed in claim 6 stretches buffer hydraulic system, it is characterized in that: described control cock comprises inserted valve and change-over valve, the end face hydraulic fluid port of described inserted valve can be connected to described first actuator port communicatively, the anchor ring hydraulic fluid port of described inserted valve can be connected to described rod chamber communicatively, and the spring cavity hydraulic fluid port of described inserted valve is optionally communicated in by described change-over valve and controls oil sources or fuel tank.
8. crane arm as claimed in claim 7 stretches buffer hydraulic system, and it is characterized in that: described control cock also comprises flow regulating valve, described flow regulating valve is arranged on the oil circuit between the spring cavity hydraulic fluid port of described inserted valve and described change-over valve.
9. crane arm as claimed in claim 7 stretches buffer hydraulic system, it is characterized in that: described control cock also comprises the first by pass valve and the second by pass valve; The oil inlet of described first by pass valve is connected to the anchor ring hydraulic fluid port of described inserted valve, and outgate is connected to described first actuator port or fuel tank; The oil inlet of described second by pass valve is connected on the oil circuit between the spring cavity hydraulic fluid port of described inserted valve and described change-over valve, and outgate is connected to fuel tank or described first actuator port.
10. a hoisting crane, is characterized in that: the described hoisting crane crane arm be provided with described in any one of claim 1 to 9 stretches buffer hydraulic system.
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| CN201510061037.XA CN104692266B (en) | 2015-02-05 | 2015-02-05 | Hydraulic system for telescopic buffer of crane boom and crane |
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| CN201510061037.XA CN104692266B (en) | 2015-02-05 | 2015-02-05 | Hydraulic system for telescopic buffer of crane boom and crane |
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| CN104692266B CN104692266B (en) | 2017-03-22 |
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Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105967076A (en) * | 2016-07-21 | 2016-09-28 | 三汽车起重机械有限公司 | Double-cylinder freely-telescopic hydraulic control system and crane comprising same |
| 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 |
| CN106185633A (en) * | 2016-08-24 | 2016-12-07 | 三汽车起重机械有限公司 | Balancing valve apparatus, crane and elevating mechanism |
| CN109202170A (en) * | 2018-11-15 | 2019-01-15 | 长沙思胜智能设备有限公司 | The main hydraulic system and broaching machine of broaching machine |
| CN110980528A (en) * | 2019-11-19 | 2020-04-10 | 徐州重型机械有限公司 | Novel single-cylinder plug pin type telescopic system and control method |
| CN112408222A (en) * | 2020-12-09 | 2021-02-26 | 广汉市正诚液压机械制造有限公司 | Tower device falls in tower crane emergency |
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| CN113586557A (en) * | 2021-07-23 | 2021-11-02 | 三一汽车制造有限公司 | Arm support control method, device and system of pumping vehicle and pumping vehicle |
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001294393A (en) * | 2000-04-07 | 2001-10-23 | Tadano Ltd | Crane hook suspension length holding device |
| JP2002321892A (en) * | 2001-04-27 | 2002-11-08 | Tadano Ltd | Hook suspending length holder |
| CN102011762A (en) * | 2010-12-16 | 2011-04-13 | 广州华研精密机械有限公司 | Backpressure and rapid pressure-relieving control device for hydraulic cylinder |
| WO2012019498A1 (en) * | 2010-08-13 | 2012-02-16 | 长沙中联重工科技发展股份有限公司 | Hydraulic control circuit and method |
| CN102583173A (en) * | 2011-12-19 | 2012-07-18 | 徐州重型机械有限公司 | Suspension arm telescopic hydraulic control system and crane with same |
| CN102807168A (en) * | 2012-08-13 | 2012-12-05 | 三一重工股份有限公司 | Hydraulic control system of single-cylinder telescoping mechanism of crane and crane |
| CN202937013U (en) * | 2012-12-05 | 2013-05-15 | 中联重科股份有限公司 | Boom hydraulic system, boom system and concrete pumping equipment |
| CN103420290A (en) * | 2013-07-25 | 2013-12-04 | 三一汽车起重机械有限公司 | Telescopic protection system and crane |
-
2015
- 2015-02-05 CN CN201510061037.XA patent/CN104692266B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001294393A (en) * | 2000-04-07 | 2001-10-23 | Tadano Ltd | Crane hook suspension length holding device |
| JP2002321892A (en) * | 2001-04-27 | 2002-11-08 | Tadano Ltd | Hook suspending length holder |
| WO2012019498A1 (en) * | 2010-08-13 | 2012-02-16 | 长沙中联重工科技发展股份有限公司 | Hydraulic control circuit and method |
| CN102011762A (en) * | 2010-12-16 | 2011-04-13 | 广州华研精密机械有限公司 | Backpressure and rapid pressure-relieving control device for hydraulic cylinder |
| CN102583173A (en) * | 2011-12-19 | 2012-07-18 | 徐州重型机械有限公司 | Suspension arm telescopic hydraulic control system and crane with same |
| CN102807168A (en) * | 2012-08-13 | 2012-12-05 | 三一重工股份有限公司 | Hydraulic control system of single-cylinder telescoping mechanism of crane and crane |
| CN202937013U (en) * | 2012-12-05 | 2013-05-15 | 中联重科股份有限公司 | Boom hydraulic system, boom system and concrete pumping equipment |
| CN103420290A (en) * | 2013-07-25 | 2013-12-04 | 三一汽车起重机械有限公司 | Telescopic protection system and crane |
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105967076A (en) * | 2016-07-21 | 2016-09-28 | 三汽车起重机械有限公司 | Double-cylinder freely-telescopic hydraulic control system and crane comprising same |
| CN105967076B (en) * | 2016-07-21 | 2017-12-08 | 三一汽车起重机械有限公司 | A kind of free telescopic hydraulic control system of twin-tub and its crane |
| 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 |
| CN106185633A (en) * | 2016-08-24 | 2016-12-07 | 三汽车起重机械有限公司 | Balancing valve apparatus, crane and elevating mechanism |
| CN106185633B (en) * | 2016-08-24 | 2018-02-23 | 三一汽车起重机械有限公司 | Balancing valve apparatus, crane and elevating mechanism |
| CN109202170A (en) * | 2018-11-15 | 2019-01-15 | 长沙思胜智能设备有限公司 | The main hydraulic system and broaching machine of broaching machine |
| CN110980528A (en) * | 2019-11-19 | 2020-04-10 | 徐州重型机械有限公司 | Novel single-cylinder plug pin type telescopic system and control method |
| CN112408222A (en) * | 2020-12-09 | 2021-02-26 | 广汉市正诚液压机械制造有限公司 | Tower device falls in tower crane emergency |
| CN112661015A (en) * | 2020-12-09 | 2021-04-16 | 中联重科股份有限公司 | Plug-in type hydraulic valve, single-cylinder plug pin type suspension arm hydraulic control system and crane |
| CN113586557A (en) * | 2021-07-23 | 2021-11-02 | 三一汽车制造有限公司 | Arm support control method, device and system of pumping vehicle and pumping vehicle |
| CN113586557B (en) * | 2021-07-23 | 2023-11-17 | 三一汽车制造有限公司 | Arm support control method, device and system of pumping vehicle and pumping vehicle |
| 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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