CN102562699B - Balanced valve, hydraulic cylinder expansion control loop and crane - Google Patents

Balanced valve, hydraulic cylinder expansion control loop and crane Download PDF

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Publication number
CN102562699B
CN102562699B CN201110424886.9A CN201110424886A CN102562699B CN 102562699 B CN102562699 B CN 102562699B CN 201110424886 A CN201110424886 A CN 201110424886A CN 102562699 B CN102562699 B CN 102562699B
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China
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main valve
chamber
valve
acting
equilibrium
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CN201110424886.9A
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Chinese (zh)
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CN102562699A (en
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左春庚
陶军
张劲
谢海波
宋建清
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中联重科股份有限公司
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Publication of CN102562699A publication Critical patent/CN102562699A/en
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Abstract

The invention provides balanced valve which comprises a main valve body (1) and a main valve core (4), wherein the main valve body (1) is provided with a positive oil outlet (A) and a reverse oil outlet (B); the main valve core (4) comprises a first acting surface (A1) and a second acting surface (A2) which are opposite to each other; the first acting surface is exposed in a first acting cavity (3) communicated with the reverse oil outlet; the second acting surface is exposed in a second acting cavity (17) communicated with the reverse oil outlet through a dumping groove (5); and the balanced valve further comprises a guiding control module which enables the second acting cavity to be selectively communicated with an oil draining port through a guiding control oil port (X). In addition, the invention also provides a hydraulic cylinder expansion control loop and a hydraulic crane. Due to the guiding control method, a large control ratio can be obtained through controlling the size of a guiding piston rod, the descending speed limitation control of the balanced valve is more sensitive, the influence of the load pressure on the openness of the main valve core is slight, frequent shaking can not be generated, the work stability is good, and the energy-saving effect is excellent.

Description

Equilibrium valve, flexible control loop of hydraulic cylinder and hoist

Technical field

The present invention relates to a kind of equilibrium valve, particularly, relate to a kind of equilibrium valve.On this basis, the invention still further relates to a kind of flexible control loop of hydraulic cylinder that is provided with described equilibrium valve.In addition, the invention still further relates to a kind of hoist.

Background technique

Equilibrium valve is a kind of valve extensively adopting on engineering mechanical device, and the service behaviour of its some hydraulic work mechanisms to betterment works machinery has important function, lifting mechanism, jib lubbing mechanism and the extending means etc. of such as hydraulic hoist.Typically, these operation mechanisms adopt oil hydraulic cylinder as hydraulic actuator, and oil hydraulic cylinder need to carry out extension and contraction control by flexible control loop of hydraulic cylinder, and equilibrium valve operated by rotary motion is in the working oil path of rodless cavity that is connected in oil hydraulic cylinder.

When the lifting mechanism bringing onto load of hydraulic hoist declines, if there is no equilibrium valve, the decline that can exceed the speed limit under the effect of load of this lifting mechanism, thus be easy to cause engineering accident.In order to prevent this dangerous phenomenon, need on the decline oil circuit of flexible control loop of hydraulic cylinder (being the working oil path of the above-mentioned rodless cavity that is connected in oil hydraulic cylinder), equilibrium valve be set, thereby play, prevent that weight from accelerating the function declining.In addition, at the lifting mechanism of hydraulic hoist, load is risen and is raised to certain altitude and while needing temporary transient hovering because of operation, equilibrium valve is in blocking, thereby can play locking effect, prevent the hydraulic oil oil return in the rodless cavity of oil hydraulic cylinder, make load be supported in this height and position, can not decline because of load weight.Certainly, at this, it should be noted that, equilibrium valve is not limited to be applied in flexible control loop of hydraulic cylinder, it is widely used in the multiple hydraulic pressure operation mechanism of engineering mechanical device, for example, in All Hydraulic Travelling System, in order to prevent descending, time hypervelocity glides, and also needs to arrange equilibrium valve in the hydraulic control circuit of this All Hydraulic Travelling System.Therefore, equilibrium valve is as independently valve of one, and it can be applied to and well known to a person skilled in the art various applications, in the following description, in order to help skilled in the art to understand, mainly as an example of typical flexible control loop of hydraulic cylinder example, be described.

Equilibrium valve is the valve being formed in parallel by one-way valve and sequence valve the most simply, but this equilibrium valve is due to sealing and the not ideal enough and less employing in engineering machinery of stable working.On engineering mechanical device, adopt custom-designed equilibrium valve, for example U.S. Pat 6,098, the equilibrium valve adopting in 647 disclosed flexible control loop of hydraulic cylinders, this equilibrium valve is the equilibrium valve of the prior art that on engineering mechanical device, typical case adopts.

Fig. 1 and Fig. 2 show sectional structure schematic diagram and the hydraulic schematic diagram of the prior art equilibrium valve.As shown in Figure 1, the equilibrium valve of the prior art mainly comprises that valve body 101, main valve plug 102, main spool spring 103, Returnning spring 105, guide piston 104 form, it has three functions, rise oil feeding function, locking keeps function and decline speed limiting function, referring to Fig. 1 and Fig. 2, specifically describes this three functional statuses:

Rising oil-feed state: forward hydraulic fluid port A connects hydraulic oil (generally switch oil circuit by the selector valve in flexible control loop of hydraulic cylinder and make forward hydraulic fluid port A oil-feed), at this, need to annotatedly be, for equilibrium valve, its forward hydraulic fluid port refers to when from this forward hydraulic fluid port oil-feed, as long as hydraulic oil has enough pressure, equilibrium valve meeting conducting, thus for example pass through this equilibrium valve, to hydraulic actuator (oil hydraulic cylinder) fuel feeding; Oppositely hydraulic fluid port refers to when from this reverse hydraulic fluid port oil-feed, and for example, if this equilibrium valve is not controlled to (hydraulic control), no matter the pressure of hydraulic oil is much, and equilibrium valve all can conducting, and this is similar with reverse hydraulic fluid port with the forward hydraulic fluid port of one-way valve.Referring to Fig. 1 and Fig. 2, when the input pressure of forward hydraulic fluid port A is not set up, the tapering part of main valve plug 102 forms sealing line with valve body 101 and contacts under the pressure of main spool spring 103, and forward hydraulic fluid port A is not communicated with reverse hydraulic fluid port B, and therefore equilibrium valve can not be opened; When the input pressure of forward hydraulic fluid port A is enough, input pressure promotion main valve plug 102 overcomes the elastic force of main spool spring 103, thereby forward hydraulic fluid port A is communicated with reverse hydraulic fluid port B, equilibrium valve is opened, now for example in flexible control loop of hydraulic cylinder, hydraulic oil is the rodless cavity fuel feeding to oil hydraulic cylinder via equilibrium valve, thereby makes the piston rod of oil hydraulic cylinder increase, and promotes load and rises.

Locking hold mode: when the not oil-feed of A of forward hydraulic fluid port and pilot control hydraulic fluid port X without pressure or pressure too hour, oppositely hydraulic fluid port B is communicated with the rodless cavity of for example oil hydraulic cylinder, under the pressure-acting of load, hydraulic oil in rodless cavity acts on the right side of main valve plug 102 via the throttling oil duct on main valve plug 102, thereby the tapering part that makes main valve plug 102 presses against on all lug, nibs of the ring of the valve pocket in valve body 101 under the acting in conjunction of this hydraulic oil and main spool spring 103, thereby form sealing more closely, oppositely hydraulic fluid port B and forward hydraulic fluid port A are in blocking state, make equilibrium valve keep closing, hydraulic oil in the rodless cavity of oil hydraulic cylinder cannot be from reverse hydraulic fluid port B via forward hydraulic fluid port A oil return, thereby realize latch functions, make load can remain on for a long time certain height and position.

Decline speed limit state: when flexible control loop of hydraulic cylinder need to be controlled oil hydraulic cylinder band dynamic load decline, (pilot control hydraulic fluid port X is generally connected in the rod chamber working oil path of oil hydraulic cylinder by pilot control hydraulic fluid port X, to carry out hydraulic control, wherein drain tap L is mainly used in Returnning spring chamber releasing of the hydraulic oil that infiltrates), when the pressure of hydraulic control hydraulic fluid port X hour, guide piston 104 cannot overcome the pretightening force of Returnning spring 105, and guide piston 104 is in the limit on the right-right-hand limit position shown in Fig. 1; When the oil pressure of guide's control port X increases gradually, thereby in the time of can promoting guide piston 104 and overcome the elastic force of Returnning spring 105, guide piston 103 moves to left, when moving to behind precalculated position, start to contact with the left end of main valve plug 102, then along with the increase of pilot pressure, guide piston 104 promotes main valve plug 102 and overcomes the elastic force of main spool spring 103, thereby reverse hydraulic fluid port B is communicated with forward hydraulic fluid port A, thereby make the hydraulic oil in the rodless cavity of oil hydraulic cylinder can oil return, thereby realize decline speed limiting function.

Shown in Figure 1, the equilibrium valve of prior art, when realizing decline speed limiting function, because guide's hydraulic control oil pressure acts on guide piston 104, and promotes main valve plug 102 by guide piston 104 and moves, and therefore its control ratio is 1/K (wherein K=D 2/ d 2d is the through-flow internal diameter of the valve pocket in the valve body 101 shown in Fig. 1, d is the control oil acting surface diameter of guide piston 104), the namely ratio of induced pressure and control oil pressure, under the situation that is 1MPa at induced pressure, controlling oil pressure need to reach and under the situation of K × 1MPa, could promote main valve stem 102 (above-mentioned control ratio is only theoretical value, and the elastic force of wherein having ignored Returnning spring 105 and main spool spring 103 affects).The equilibrium valve of this prior art is due to the reason of structural design, the problem that exists some to be difficult to overcome, for example, because D is determined by the through-current capability of equilibrium valve, this need to the operating rate of hydraulic work mechanism, the factor couplings such as the traffic demand of hydraulic actuator, hydraulic work mechanism need to select the equilibrium valve of through-current capability coupling according to application, therefore the size of this D is determined relatively, d belongs to oil circuit control part simultaneously, it can not form greatlyr, otherwise can cause controlling low on fuel, control the defects such as difficulty, therefore the control ratio of the equilibrium valve of the prior art is larger comparatively speaking.In this case, in the decline speed limit process of equilibrium valve, although it can realize decline speed limiting function, but too responsive to the variation of induced pressure, once induced pressure slightly changes, require the control oil pressure of coupling to change at double, otherwise the aperture of equilibrium valve will produce significant change, and in hydraulic work mechanism working procedure, induced pressure because of a variety of causes be often to change (especially adopt in the hydraulic work mechanism of multi-stage expansion cylinder), even if induced pressure is only slightly to fluctuate, the aperture of equilibrium valve also can frequently change, thereby the equilibrium valve that makes the prior art is subject to induced pressure impact, very easily produce frequent shake and wait job insecurity phenomenon, for another example, larger just because of above-mentioned control ratio, therefore equilibrium valve cracking pressure when realizing decline speed limiting function is large, causes power loss large.Therefore, the aperture of the equilibrium valve of this prior art is because being subject to load effect, and it is controlled poor, even when the oil pressure of pilot control hydraulic fluid port X keeps constant, still cannot maintain the stable aperture of equilibrium valve.

From upper description, the major defect of the equilibrium valve of the prior art is: first, due to the reasons in structure of this equilibrium valve, its control ratio is unreasonable, thereby controlled poor, and job insecurity, although it can realize decline speed limiting function, but it is too responsive that equilibrium valve changes induced pressure, easily there is the phenomenon of the job insecurities such as frequent shake; The second, the aperture of equilibrium valve cannot realize relatively stable control reliably by pilot control hydraulic fluid port X, even if be also difficult for realizing stable control when underloading; The 3rd, pilot pressure is higher, for realizing certain control ratio, usually reluctantly the area of the control oil acting surface of guide piston 104 is formed greatlyr artificially, cause controlling sensitivity more undesirable, and energy consumption loss is larger.

Therefore, need to design a kind of novel equilibrium valve, to overcome or to alleviate an above-mentioned even whole shortcoming of prior art.

Summary of the invention

Technical problem to be solved by this invention is to provide a kind of equilibrium valve, and this equilibrium valve not only can be realized the hydraulic function of equilibrium valve effectively, and controlled good, working stability.

On this basis, the further technical problem to be solved of the present invention is to provide a kind of flexible control loop of hydraulic cylinder, this flexible control loop of hydraulic cylinder carries in load decline process and can effectively realize speed limiting function at oil hydraulic cylinder, and working stability is good, significantly improved the reliability of control performance.

In addition, the present invention also will provide a kind of hoist, and this hoist can effectively be realized steadily the hoisting of load, locking keeps and decline speed limiting function, and working stability is good, and control performance is relatively reliable.

In order to solve the problems of the technologies described above, the invention provides a kind of equilibrium valve, this equilibrium valve comprises having forward hydraulic fluid port and the main valve body of reverse hydraulic fluid port and the main valve plug that can move in the valve pocket of this main valve body, this main valve plug is the normally closed sealing station in described forward hydraulic fluid port and reverse hydraulic fluid port are blocked under the elasticity pretightening force effect of main valve plug spring, wherein, described main valve plug comprises the first relative acting surface and the second acting surface, this first acting surface is exposed in the first acting chamber being communicated with described reverse hydraulic fluid port, the action direction that is subject to force direction and described elasticity pretightening force of this second acting surface is identical and be exposed in the second acting chamber being communicated with described reverse hydraulic fluid port via damping slot or damping hole, between this second acting chamber and the drain tap of described equilibrium valve, be provided with draining oil duct, described equilibrium valve also comprises pilot control module, this pilot control module comprises the guide piston with guide piston bar that can move back and forth, Returnning spring and be positioned at the liquid controling cavity of this guide piston one side, described guide piston bar extend in described draining oil duct and under the effect of described Returnning spring and forms sealing and block this draining oil duct with the inwall of this draining oil duct, described liquid controling cavity is communicated with the pilot control hydraulic fluid port of described equilibrium valve, can receive hydraulic control oil and to control described guide piston, drive described guide piston bar to move and make the conducting of described draining oil duct.

Preferably, the main valve plug spring chamber of described main valve plug spring doubles as described the second acting chamber.

Preferably, described the second acting chamber is communicated with described reverse hydraulic fluid port by described damping slot, this damping slot is formed on the outer circumferential face of described main valve plug, and by increase the through-flow aperture of this damping slot in described main valve plug moves away the process of described normality sealing station with the coordinating of valve pocket inwall of described main valve body.

Particularly, on the valve pocket inner peripheral surface of described main valve body, form the projection with axial slope coordinating with described damping slot, this projection moves away in the process of described normality sealing station with the distance of the diapire of described damping slot and increases at described main valve plug, to increase the through-flow aperture of this damping slot.

Preferably, the area of described the first acting surface is less than the area of described the second acting surface.

Preferably, on described guide piston bar, be formed with throttling groove, the through-flow aperture of this throttling groove is along with described guide piston bar moves away with the position of the inner wall sealing of described draining oil duct and increases.

Particularly, described draining oil duct comprises that piston rod coordinates through hole, and described guide piston bar extend into this piston rod and coordinates in through hole and under the effect of described Returnning spring, coordinate through hole to form conical surface seal with described piston rod.

Particularly, described guide piston bar comprises throttling groove section, the cross sectional area of this throttling groove section reduces the described throttling groove increasing continuously to form cross sectional area on described guide piston bar continuously, when described guide piston bar moves away the position that coordinates through hole sealing with described piston rod, described throttling groove section moves through described piston rod and coordinates through hole to increase the through-flow aperture of described throttling groove.

Particularly, described pilot control module comprises and forms as one with described main valve body or be arranged on the guide valve blocks on this main valve body, in this guide valve blocks, be formed with the pilot spool chamber and the guide piston chamber that by described piston rod, coordinate through hole to be communicated with, described pilot spool chamber is communicated with described the second acting chamber, in described guide piston chamber, be provided with the described guide piston that can slide and be divided into Returnning spring chamber and described liquid controling cavity by this guide piston sealing, described Returnning spring is provided with described Returnning spring in chamber, and the chamber wall in this Returnning spring chamber is provided with described drain tap.

Particularly, one end part of described guide piston bar is formed as the described cone seal section that coordinates through hole to seal mutually with described piston rod, in this cone seal section, be formed with connection oil duct, and this cone seal section is connected with the pilot spool being sealed and matched with the inner peripheral surface in described pilot spool chamber, in this pilot spool, be provided with the fixing damping hole that is communicated with described connection oil duct and the second acting chamber, described draining oil duct coordinates through hole, throttling groove and Returnning spring chamber to form by described fixing damping hole, connection oil duct, piston rod.

Alternative ground, one end part of described guide piston bar is provided with the cone match part that coordinates through hole to seal mutually with described piston rod, this cone match part is positioned at described pilot spool chamber and is fixed on described guide piston bar by locking nut, and described draining oil duct coordinates through hole, throttling groove and Returnning spring chamber to form by described pilot spool chamber, piston rod.

Alternative ground, one end part of described guide piston bar is connected with or is formed with and is positioned at described pilot spool chamber and the sealing column with the inner peripheral surface interval in this pilot spool chamber, sealing post has the conical surface part that coordinates through hole to be sealed and matched with described piston rod, and described draining oil duct coordinates through hole, throttling groove and Returnning spring chamber to form by described pilot spool chamber, piston rod.

Particularly, in described main valve body, be provided with main valve housing, the valve pocket of described main valve body forms by this main valve housing, and described the first acting chamber, the second acting chamber and main valve plug spring chamber formed by described main valve plug and coordinating of this main valve housing.

On the basis of above-mentioned equilibrium valve technological scheme, the present invention also provides a kind of flexible control loop of hydraulic cylinder, this flexible control loop of hydraulic cylinder comprises equilibrium valve and selector valve, wherein, described equilibrium valve is the equilibrium valve described in any one in technique scheme, the forward hydraulic fluid port of this equilibrium valve is communicated with an actuator port of described selector valve, oppositely hydraulic fluid port is communicated with the rodless cavity of oil hydraulic cylinder, pilot control hydraulic fluid port is communicated with the working oil path of the rod chamber that is connected in described oil hydraulic cylinder, and unloading port is communicated with fuel tank or oil return circuit.

In addition, the present invention also provides a kind of hoist, and wherein, this hoist comprises above-mentioned flexible control loop of hydraulic cylinder.

Pass through technique scheme, equilibrium valve of the present invention optionally makes the second acting chamber (preferably by the movement of guide piston bar, main valve plug spring chamber doubles as this second acting chamber) be communicated with fuel tank or oil return circuit, thereby by controlling the movement of guide piston bar, control the movement of main valve plug, it adopts pilot control mode, therefore only need the geomery of controlling guide piston bar can easily obtain larger control ratio, this makes the decline Control for Speed Limitation of equilibrium valve sensitiveer, by less control oil pressure, can effectively control the unlatching of main valve plug, and the aperture of main valve plug is affected not quite by induced pressure, it depends primarily on the oil pressure of pilot control oil port, thereby can not produce frequent shake because of the summary microvariations of induced pressure, better working stability.In addition, under optimal way, the second acting chamber can increase through-current capability, reduction damping function damping slot by moving axially along with main valve plug is communicated with reverse hydraulic fluid port, this can make equilibrium valve control better effects if of the present invention, make to form a kind of relative transient equiliblium between the first acting chamber and the second acting chamber, avoid the aperture of main valve plug excessive.In addition, on described guide piston bar, can be integrated with throttling groove, the movement along with guide piston bar when guide's control port has enough oil pressure of this throttling groove increases aperture gradually, or when reducing, the oil pressure of guide's control port reduces gradually aperture, therefore stable working is better, has avoided the impact phenomenon in working procedure.Meanwhile, because the length of the second chute on guide piston bar can form longlyer, thereby controlled better.In addition,, because required control oil pressure is less, therefore energy-saving effect is good.Apparently, because flexible control loop of hydraulic cylinder of the present invention and hydraulic hoist comprise above-mentioned equilibrium valve of the present invention, therefore it also has above-mentioned technological merit.

Other features and advantages of the present invention are described in detail the embodiment part subsequently.

Accompanying drawing explanation

Following accompanying drawing is used to provide a further understanding of the present invention, and forms the part of specification, and itself and following embodiment one are used from explanation the present invention, but protection scope of the present invention is not limited to following the drawings and the specific embodiments.In the accompanying drawings:

Fig. 1 and Fig. 2 are respectively sectional structure schematic diagram and the hydraulic schematic diagrams of the equilibrium valve of prior art.

Fig. 3 is the sectional structure schematic diagram of the equilibrium valve of the specific embodiment of the invention.

Fig. 4 is the local enlarged diagram at the throttling groove position on the guide piston bar of the equilibrium valve shown in Fig. 3.

Fig. 5 is the hydraulic principle schematic diagram of the equilibrium valve of the specific embodiment of the invention shown in Fig. 3.

Fig. 6 and Fig. 7 are the local enlarged diagrams of another two kinds of concrete forms of implementation at the throttling groove position on the guide piston bar of respectively equilibrium valve of the present invention.

Description of reference numerals of the present invention:

1 main valve body; 2 main valve housings;

3 first acting chambers; 4 main valve plugs;

5 damping slots; 6 main valve plug springs;

7 main valve plug spring chambers; 8 pilot spools;

9 fixing damping holes; 10 are communicated with oil duct;

11 pilot spool chambeies; 12 guide valve blocks;

13 Returnning spring chambeies; 14 Returnning springs;

15 guide piston bars; 16 guide pistons;

17 second acting chambers; 18 liquid controling cavities;

19 draining oil ducts;

136 pilot spool chamber inner peripheral surfaces;

137 sealing column; 138 locking nuts;

139 cone match parts; 140 cone seal sections;

141 piston linkage sections; 142 first segment chute sections;

143 second section chute sections; 144 the 3rd throttling groove sections;

145 throttling grooves; A forward hydraulic fluid port;

The reverse hydraulic fluid port of B; A1 the first acting surface;

A2 the second acting surface; L drain tap;

Oil pressure in P1 the first acting chamber;

Oil pressure in P2 the second acting chamber;

X pilot control hydraulic fluid port.

Embodiment

Below in conjunction with accompanying drawing, the specific embodiment of the present invention is elaborated, should be understood that, embodiment described herein is only for description and interpretation the present invention, and protection scope of the present invention is not limited to following embodiment.

First it should be noted that, equilibrium valve of the present invention belongs to hydraulic element, and its core technology design is its hydraulic control relation, and does not lie in concrete valve mechanism.Fig. 3, concrete valve mechanism shown in Fig. 4 and Fig. 6 and Fig. 7 is only to help skilled in the art to understand and the specific constructive form that exemplifies, but protection scope of the present invention should be confined to these specific constructive form, for example, with regard to the hydraulic control relation of the preferred form of the equilibrium valve of the present invention shown in Fig. 5, under the technology enlightenment of this hydraulic control relation, those skilled in the art can expect various concrete valve mechanisms, but, no matter how modification of concrete valve mechanism form, as long as it adopts the hydraulic control relation of equilibrium valve of the present invention, it all belongs to protection scope of the present invention.

In order to help those skilled in the art profoundly to understand technological scheme of the present invention, first the preferred specific constructive form of one of equilibrium valve of the present invention is below described, to make those skilled in the art begin to take shape understanding more intuitively to technological scheme of the present invention with reference to Fig. 3 and Fig. 4.But; protection scope of the present invention is not limited to the detail structure shown in Fig. 3 and Fig. 4; for this reason on the basis of this preferred valve structure, the technological scheme on broad sense level (being hydraulic control relational hierarchy) more that present invention will be further described.

As shown in Figure 3, illustrated equilibrium valve comprises and is formed with forward hydraulic fluid port A and the oppositely main valve body 1, main valve housing 2, main valve plug 4, main valve plug spring 6, guide valve blocks 12, Returnning spring 14, guide piston 16, guide piston bar 15 etc. of hydraulic fluid port B, wherein main valve plug 4 and main valve housing 2 coordinate vertically, one place's Cone fit face is to form conical surface seal, one place's cylindrical fit face, main valve plug 4 forms conical surface seal with main valve housing 2 under the elasticity pretightening force effect of main valve plug spring 6, with the normality sealing station in forward hydraulic fluid port A and reverse hydraulic fluid port B are blocked.

Simultaneously main valve plug 4 also comprise for pressurized with drive this main valve plug to leave the first acting surface A1 of described normality sealing station and for pressurized this main valve plug 4 is kept or shifts to the second acting surface A2 of described normality sealing station, the first acting surface A1 is exposed in the first acting chamber 3 being communicated with described reverse hydraulic fluid port B, this the first acting surface A1 and main valve housing 2 surround the first acting chamber 3 jointly, can receive from the hydraulic oil of reverse hydraulic fluid port B and to bear the pressure of this hydraulic oil, the second acting surface A2 is exposed in the main valve plug spring chamber 7 being communicated with reverse hydraulic fluid port B via damping slot 5, this main valve plug spring chamber 7 is by the second acting surface A2, the side of main valve housing 2 and guide valve blocks 12 surrounds jointly, in the mode of execution shown in Fig. 3, in fact main valve plug spring chamber 7 doubles as the second acting chamber moving for controlling main valve plug 4, damping slot 5 is formed on the outer circumferential face of main valve plug 4, this damping slot 5 is also shown in the hydraulic schematic diagram shown in Fig. 5.Preferably, this damping slot 5 along with main valve plug 4 from the normality sealing station that makes reverse hydraulic fluid port B and forward hydraulic fluid port A and block to the process that the controlled conduction position of reverse hydraulic fluid port B and forward hydraulic fluid port A conducting is moved and increase through-flow aperture, this is that appearance is intelligible for those skilled in the art, this is generally matched and realizes with the inner peripheral surface of main valve housing 2 by main valve plug 4, for example on main valve plug 4, be formed with damping slot 5, on the inner peripheral surface of main valve housing 2, form the projection with axial slope coordinating with this damping slot 5, along with main valve plug 4 moves with respect to main valve housing 2, the distance of the diapire of projection and damping slot 5 increases, thereby increased the aperture of damping slot 5, increased through-current capability.Main valve plug spring 6 one end are arranged on the bump of main valve plug 4 one end, and the other end is installed on the side that is supported on guide valve blocks 12.Guide piston bar 15 can be assembled together vertically by the modes such as welding, riveted joint and pilot spool 8.Pilot spool 8 is positioned at the pilot spool chamber 11 of guide valve blocks 12, and coordinates with the inner peripheral surface in the pilot spool chamber 11 of guide valve blocks 12, to make the motion of guide piston bar 16 more steady.The connection oil duct 10 that is formed with a fixing damping hole 9 in pilot spool 8 and is communicated with this fixing damping hole, main valve plug spring chamber 7 is communicated with pilot spool chamber 11 via this fixing damping hole 9 and connection oil duct 10.

Guide valve blocks 12 sealings are arranged on main valve body 1, in this guide valve blocks 12, be formed with pilot spool chamber 11 and guide piston chamber, this pilot spool chamber 11 and guide piston chamber coordinate through hole 20 to be communicated with by the piston rod being formed on guide valve blocks 12, pilot spool chamber 11 is communicated with main valve plug spring chamber 7, in guide piston chamber, be provided with the guide piston 16 that can slide and be divided into Returnning spring chamber 13 and liquid controling cavity 18 by these guide piston 16 sealings, liquid controling cavity 18 is communicated with the pilot control hydraulic fluid port X of equilibrium valve, can receive hydraulic control oil and to control guide piston 16, drive guide piston bar 15 to move.In Returnning spring chamber 13, be provided with Returnning spring 14, and the chamber wall in this Returnning spring chamber 13 is provided with drain tap L.Guide piston bar 15 extend into piston rod and coordinates in through hole 20 and under the effect of described Returnning spring 14, coordinate through hole 20 to form conical surface seal with piston rod, when the hydraulic fluid pressure in liquid controling cavity 18 is enough to overcome the elastic force of Returnning spring 14 and the hydraulic oil of main valve plug spring chamber 7 to the pressure of guide piston bar 15, guide piston bar 15 is driven and is moved away the position that coordinates through hole 20 to seal mutually with piston rod.Throttling groove 145 structures on conical surface seal and the guide piston bar of guide piston bar 15 and piston rod cooperation through hole 20 as shown in Figure 4, correspondingly, this embodiment guide piston bar 15 comprises cone seal section 140, throttling groove section and piston linkage section 141, wherein between the cone seal section 140 of guide piston bar 15 and piston rod cooperation through hole 20, form cone seal, this conical section is formed with conical seal (contact) face.In order to form throttling groove 145 on guide piston bar 15, the cross sectional area of the throttling groove section of guide piston bar 15 need to have corresponding variation, to make the throttling groove section of guide piston bar 15 form corresponding throttling groove 145, particularly, the throttling groove section of guide piston bar 15 can be subdivided into three sections, between the inner peripheral surface that first segment chute section 142 and piston rod coordinate through hole 20 to match, only have small gap, the cross-section area of ensuing second section chute section 143 reduces gradually; And then connect down the 3rd throttling groove section 144 cross-section areas continue reduce gradually finally to remain unchanged.The cross-section area of the piston linkage section 141 of guide piston bar 15 is identical with the cross sectional area of first segment chute section 142, and this piston linkage section 141 is connected with guide piston 16.Returnning spring 14 one end are arranged on the side of guide piston 16, and the other end is installed and is supported on the inner side surface in Returnning spring chamber 13 of guide valve blocks 12.

From upper description, the technical characteristics of the equilibrium valve of above-mentioned preferred implementation is to adopt pilot control mode, controls the aperture of main valve plug by controlling the movement of guide piston bar, and the control ratio of this equilibrium valve is similar to can think D 2/ d 2wherein D is the external diameter of guide piston 16, d is the external diameter of the piston linkage section 141 of guide piston bar 15, that is to say, by the less control oil pressure at pilot control hydraulic fluid port X place, can make main valve plug 4 open, even and if induced pressure slightly changes, the main valve plug aperture of equilibrium valve also can responsively not change, thereby more stable work is reliable, is not easy to produce the phenomenon of the job insecurities such as shake, and control sensitiveer, controlled good.In addition, this equilibrium valve also has following structure characteristic: first, the throttling groove that this equilibrium valve moves the main valve plug 4 of controlling equilibrium valve is integrated on guide piston bar, this throttling groove forms continuously in the throttling groove section 142,143,144 of guide piston bar, it is through-flow, and aperture changes, along with guide piston bar 15 is to the left side motion shown in Fig. 3 and increase through-flow aperture, move right and reduce through-flow aperture, its by the Structure Improvement of simplifying the performance of equilibrium valve; Second, this equilibrium valve makes main valve plug spring chamber 7 double as the second acting chamber, thereby make balancing valve structure of the present invention compacter, this main valve plug spring chamber 7 can increase through-current capability, reduction damping function damping slot 5 by moving axially along with main valve plug is communicated with reverse hydraulic fluid port, this can make equilibrium valve control better effects if of the present invention, make to form between the first acting chamber and the second acting chamber and form a kind of relative transient equiliblium, avoid the aperture of main valve plug excessive; The 3rd, this equilibrium valve is by forming fixing damping hole 9 in pilot spool 8, make by the pressure release of main valve plug spring chamber 7 too fast, thereby guarantee that main valve plug spool steadily moves; The 4th, on described guide piston bar, be integrated with throttling groove 145, the movement along with guide piston bar when guide's control port has enough oil pressure of this throttling groove increases aperture gradually, or when reducing, the oil pressure of guide's control port reduces gradually aperture, therefore stable working is better, has avoided the impact phenomenon in working procedure.Because the Main Function of the throttling groove on guide piston bar 15 is by the pressure decreased of spring chamber 7, therefore the mounting point of guide piston 16, guide piston bar 15, guide valve blocks 12 can be selected as the case may be, both can be arranged on the axial position shown in Fig. 3, also can be arranged on the position angled with the axis of equilibrium valve, also can be arranged in or off plumb plane perpendicular with axis, and be not limited to the concrete form shown in Fig. 3 simultaneously.

In addition, it should be noted that, described above is only the preferred constructive form of equilibrium valve of the present invention, but equilibrium valve of the present invention is not limited to above-mentioned specific constructive form, for example shown in Figure 6, the pilot spool 8 and the fixing damping hole 9 that on guide piston bar 15, connect also can be cancelled, locking nut 138 fixed axoid counterparts 139 are passed through in one end at guide piston bar 15, these cone match part 139 roles cone seal section of guide piston bar 15 in above-mentioned preferred implementation is similar, mainly to coordinate through hole 20 to form conical surface seal by the conical surface on this cone match part 139 with the piston rod of guide valve blocks 12, also can play backstop action to guide piston bar 15 simultaneously, prevent the excessively mobile active position that loses normal work of guide piston bar 15, similar with above-mentioned optimal way, guide piston bar 15, guide piston 16, guide valve blocks 12, cone match part 139, locking nut 138 grades can be arranged on the axial position of equilibrium valve, but also can be arranged on the position angled with equilibrium valve axis, or be arranged in or off plumb plane perpendicular with equilibrium valve axis.For another example, referring to Fig. 7, the pilot spool 8 of above-mentioned preferred form and fixing damping hole 9 can also replace by the sealing column 137 shown in Fig. 7, above-mentioned pilot spool chamber inner peripheral surface 136 with the outer circumferential face of sealing post 137 without coordinating requirement, and the diameter of sealing column 137 is less than the diameter (with the inner peripheral surface interval in pilot spool chamber) in pilot spool chamber, under which, can realize equally object of the present invention.But, it should be noted that, in the alternate embodiments shown in Fig. 6 and Fig. 7, the control ratio of equilibrium valve is compared and is slightly reduced with the control ratio of above-mentioned preferred constructive form, this is the diameter that is all greater than the piston rod linkage section 141 of the guide piston bar 15 shown in Fig. 3 due to the diameter of cone match part 139 or sealing column 137, and there is not the pressure-acting face of cancelling out each other yet, therefore when calculating control ratio, should calculate with the diameter of cone match part 139 or sealing column 137.But, apparently, in these two kinds of alternate embodiments, equilibrium valve of the present invention remains movements by controlling guide piston bar 15 itself controls the aperture of main valve plug 4, and therefore optimization control ratio relatively easily, improves working stability significantly, and the sensitivity of enhancing control, thereby improve significantly the service behaviour of equilibrium valve, and by controlling the through-flow aperture of throttling groove 145, change to control the aperture of main valve plug, thereby realize approximate proportional control function to a certain degree.

What at this, need repeat specification is; by the alternate embodiments shown in this Fig. 6 and Fig. 7, also can see; within the scope of the technical conceive of equilibrium valve of the present invention; those skilled in the art can be out of shape by various concrete structures; but as long as these malformations belong to technical conceive of the present invention, it just should belong to protection scope of the present invention.Major technique design of the present invention is the hydraulic principle of its core, and protection scope of the present invention should be confined to any concrete details structure.

For this reason, by main, with reference to Fig. 5, the more technological scheme on general technique design level of the present invention is described below, on this broad sense level, technological scheme is not limited to above-mentioned preferred structure, but can comprise other the possible concrete structure within the scope of the technology of the present invention design, can be suitably with reference to Fig. 3 in order to promote understanding.

Referring to Fig. 3, just as described above, the primary valve part of equilibrium valve of the present invention and prior art equilibrium valve are substantially similar, this equilibrium valve comprises having the main valve body 1 of forward hydraulic fluid port A and reverse hydraulic fluid port B and can in the valve pocket of this main valve body 1, move the main valve plug 4 to control described forward hydraulic fluid port A and reverse hydraulic fluid port B break-make, this main valve plug 4 is the normally closed sealing station in described forward hydraulic fluid port A and reverse hydraulic fluid port B are blocked under the elasticity pretightening force effect of main valve plug spring 6, this sealing generally adopts conical surface seal, for example in Fig. 3, the conical surface of main valve plug 4 one end forms conical surface seal with the main valve housing 2 being arranged in the valve pocket of main valve plug 4, main valve plug 4 the other ends are pressed on main valve housing 2 main valve plug 4 by the pretension elastic force of main valve plug spring 6, thereby form, make main valve plug 4 sealing station that is in the normal state, so that forward hydraulic fluid port A and reverse hydraulic fluid port B are blocked.

Unlike the prior art, main valve plug 4 also comprise for pressurized with drive this main valve plug to leave the first acting surface A1 of described normality sealing station and for pressurized this main valve plug 4 is kept or shifts to the second acting surface A2 of described normality sealing station, that is to say, main valve plug 4 comprises the first relative acting surface A1 and the second acting surface A2, the wherein direction of bearing hydraulic fluid pressure of the first acting surface and the pressurized opposite direction of the second acting surface, and the second acting surface A2 be subject to force direction identical with the action direction of the elasticity pretightening force of main valve plug spring 6, can make main valve plug 4 there is the trend that remains on or shift to normality sealing station.Wherein, the first acting surface A1 is exposed in the first acting chamber being communicated with described reverse hydraulic fluid port B, can receive from the hydraulic oil of reverse hydraulic fluid port B and to bear the pressure of this hydraulic oil, the second acting surface A2 is exposed in the second acting chamber 17 being communicated with reverse hydraulic fluid port B via damping slot 5 or damping hole, to receive via damping slot 5 or damping hole the pressure that comes from the hydraulic oil of reverse hydraulic fluid port B and bear this hydraulic oil, at this, it should be noted that, due to the effect of damping slot 5 or damping hole, oil pressure in the dynamic duty process of equilibrium valve in the second acting chamber 17 generally will be lower than the oil pressure in the first acting chamber 3, for example, under the situation of sealing at the second acting chamber 17 (the locking hold mode of equilibrium valve), the oil pressure of the second acting chamber 17 interior hydraulic oil needs regular hour accumulation just can reach the degree identical with the interior hydraulic oil pressure of the first acting chamber 3, that is to say that to have certain reaction time poor.The specific constructive form of the first acting chamber 3 and the second acting chamber can be varied, for example, in the preferred structure shown in above-mentioned Fig. 3, the main valve plug spring chamber 7 of main valve plug spring 6 doubles as the second acting chamber 17, in the entity structure of valve, without independence, form the second acting chamber 17 like this, thereby simplified structure, in this case, the second acting surface A2 is exactly the right side (comprise bear the main valve plug body end face of oil pressure and for the end face of projection of main valve plug spring 6 is installed) of the main valve plug 4 shown in Fig. 3, certainly, main valve plug spring chamber 7 also can be as the second acting chamber 17, need in this case to arrange independently the second acting chamber 17.In addition, between the second acting chamber 17 and the drain tap L of described equilibrium valve, be provided with draining oil duct 19, for example in above-mentioned Fig. 3, emptying oil duct 19 coordinates through hole 20, throttling groove 145 and Returnning spring chamber 13 to form by the Returnning spring chamber 13 on the fixing damping hole 9 in pilot spool 8, connection oil duct 10, guide valve blocks 12 and the piston rod between pilot spool chamber 11; And in the substitute variants mode of execution of Fig. 6 and Fig. 7,19 of emptying oil ducts coordinate through hole 19, throttling groove 145 and Returnning spring chamber 13 to form by pilot spool chamber 11, piston rod.Apparently, those skilled in the art it will also be appreciated that other multiple concrete structural type, but these simple variant structures all should be worked as and belong to protection scope of the present invention.

In addition, equilibrium valve of the present invention also comprises pilot control module, the main body of this pilot control module is actually a control cylinder, suitably referring to Fig. 3, this pilot control cylinder module comprises the guide piston 16 with guide piston bar 15 that can move back and forth, act on the Returnning spring 14 on this guide piston 16 and be positioned at the liquid controling cavity 18 of described guide piston 16 1 sides, described guide piston bar 15 extend in described draining oil duct 19 and under the effect of described Returnning spring 14 and forms sealing with the inwall of this draining oil duct 19, thereby block this draining oil duct, liquid controling cavity 18 is communicated with the pilot control hydraulic fluid port X of equilibrium valve, thereby can receive hydraulic control oil drives guide piston 16 to move, and drive guide piston bar 15 to move away the position that forms sealing with the inwall of draining oil duct 19 by this guide piston 16, thereby make 19 conductings of draining oil duct, described the second acting chamber 17 is communicated with and the hydraulic oil in the second acting chamber is released with described drain tap L, hydraulic oil in the second acting chamber 17 is reduced.

More than describe hydraulic control of the present invention and be related to the basic technical scheme in aspect, at the technical conceive of this basic technical scheme, comprised the various possible concrete valve mechanism in the scope of the invention.Therefore, at this, need to again emphasize, no matter how modification of the concrete structure of equilibrium valve, as long as it has adopted the above-mentioned hydraulic control relation of the present invention, it all should be worked as and belong to protection scope of the present invention.On the basis of technique scheme, equilibrium valve of the present invention also comprises some preferred concrete structures, and for example main valve plug spring chamber 7 mentioned above doubles as the specific constructive form of the draining oil duct 19 in structural type, Fig. 3, Fig. 6 and Fig. 7 of the second acting chamber 3.To describe some other structural types of comparative optimization ground of equilibrium valve of the present invention below, these structural types have been carried out suitable description in the optimal way above with reference to Fig. 3, therefore following only schematic illustration.

In above-mentioned basic technical scheme, the second acting chamber 17 is communicated with described reverse hydraulic fluid port B by damping slot 5 or damping hole, that is to say, between the second acting chamber 17 and reverse hydraulic fluid port B, as long as realize, has the through-flow of damping function.But, preferably, the second acting chamber 17 is communicated with described reverse hydraulic fluid port B by specific described damping slot 5, this damping slot 5 is formed on the outer circumferential face of main valve plug 4, and by increase the through-flow aperture of this damping slot 5 in main valve plug 4 moves away the process of described normality sealing station with the coordinating of valve pocket inwall of main valve body 1.That is to say, the damping slot that this damping slot 5 can increase through-current capability for moving axially along with main valve plug, reduce damping function, it is the damping slot that through-flow aperture can change, this can make equilibrium valve control better effects if of the present invention, make to form between the first acting chamber and the second acting chamber and form a kind of relative transient equiliblium, avoid the aperture of main valve plug excessive.Particularly, the damping slot 5 of this form can be realized by various concrete structures, for example, as mentioned above, particularly, on the outer circumferential face of main valve plug 4, be formed with damping slot 5, the upper projection with axial slope (this projection has predetermined length) coordinating with this damping slot 5 that forms of valve pocket inner peripheral surface (for example inner peripheral surface of main valve housing 2) of main valve body, along with main valve plug 4 is with respect to the valve pocket motion of main valve body 1, the distance of the diapire of this projection and damping slot 5 increases, to increase the through-flow aperture of damping slot 5, thereby increase the through-current capability of damping slot 5.Certainly, damping slot 5 can be realized by various structures the through-flow aperture of above-mentioned axially variable for those skilled in the art, does not repeat them here.

In addition, the area of described the first acting surface A1 can be less than the area of described the second acting surface A2, but this is not inevitably, by selecting the main valve plug spring 6 of different elasticity coefficient, the area of the first acting surface A1 also can be greater than the area of described the second acting surface A2, certainly, and in the preferred implementation shown in Fig. 3, because main valve plug spring chamber 7 preferably doubles as the second acting chamber 17, the area of obvious the first acting surface A1 can be less than the area of the second acting surface A2.

In order to make equilibrium valve operation more steady, avoid the impact of moment cutout or conducting, on guide piston bar 15, be formed with throttling groove 145, the through-flow aperture of this throttling groove 145 is along with described guide piston bar 15 moves away with the position of the inner wall sealing of described draining oil duct 19 and increases.Particularly, for example, described in Fig. 3, draining oil duct 19 comprises that piston rod coordinates through hole 20, and guide piston bar 15 extend into this piston rod and coordinates in through hole 20 and under the effect of Returnning spring 14, coordinate through hole 20 to form conical surface seal with piston rod.Guide piston bar 15 comprises throttling groove section 142,143,144, the cross sectional area of this throttling groove section reduces the throttling groove 145 increasing continuously to form cross sectional area on described guide piston bar 15 continuously, described guide piston bar 15 moves away while coordinating the position that through hole 20 seals with described piston rod, throttling groove section 142,143,144 moves through described piston rod and coordinates through hole 20 to increase the through-current capability of described throttling groove 145.

Particularly, referring to Fig. 3, above-mentioned pilot control module of the present invention comprises and forms as one with main valve body 1 or seal the guide valve blocks 12 being arranged on this main valve body 1, in this guide valve blocks 12, be formed with the pilot spool chamber 11 and the guide piston chamber that by described piston rod, coordinate through hole 20 to be communicated with, pilot spool chamber 11 is communicated with described the second acting chamber 17, this connection can have various ways, and does not limit to and the concrete form shown in Fig. 3.As mentioned above, the concrete structure of pilot control module is actually control cylinder, in guide piston chamber, be provided with the guide piston 16 that can slide, this guide piston chamber is divided into Returnning spring chamber 13 and liquid controling cavity 18 by these guide piston 16 sealings, in Returnning spring chamber 13, be provided with described Returnning spring 14, this Returnning spring 14 has certain elasticity pretightening force and acts on guide piston 16, thereby make the tapered end of guide piston bar 15 one end or Sealing be set to press against on piston rod matching hole 20, to form conical surface seal.In addition, described drain tap L arranges on the chamber wall in Returnning spring chamber 13.In main valve body 1, be provided with main valve housing 2, the valve pocket of main valve body 1 forms by this main valve housing 2, and the first acting chamber 3, the second acting chamber 17 and main valve plug spring chamber 7 formed by described main valve plug 3 and coordinating of this main valve housing 2.In addition, some other preferred structure is described in the above-mentioned preferred embodiment with reference to Fig. 3, again repeats no more.

The working principle of preferred embodiment for the present invention equilibrium valve is mainly described below, more to embody the advantage of equilibrium valve of the present invention with reference to Fig. 3, Fig. 3 and Fig. 5.

The working principle of this equilibrium valve as shown in Figure 5, the flexible control loop of hydraulic cylinder that is wherein applied to hydraulic hoist lifting mechanism take this equilibrium valve is as example, wherein forward hydraulic fluid port A is communicated with an actuator port of the selector valve in flexible control loop of hydraulic cylinder, oppositely hydraulic fluid port B is communicated with the rodless cavity of oil hydraulic cylinder, and pilot control hydraulic fluid port X is communicated with the rod chamber working oil path of oil hydraulic cylinder.In this case, the working state of this equilibrium valve is divided into rising oil-feed state (running of hydraulic power oil direction is forward hydraulic fluid port A → oppositely hydraulic fluid port B), locking hold mode, decline speed limit state (running of hydraulic power oil direction is reverse hydraulic fluid port B → forward hydraulic fluid port A).

Rising oil-feed state: when the hydraulic oil pressure of forward hydraulic fluid port A foundation is enough to overcome the elastic force of main valve plug spring 6, hydraulic oil promotes main valve plug 4 and moves, thereby forward hydraulic fluid port A is communicated with reverse hydraulic fluid port B, hydraulic oil is the rodless cavity oil-feed to oil hydraulic cylinder via reverse hydraulic fluid port B from forward hydraulic fluid port A, thereby the piston rod that promotes oil hydraulic cylinder rises, make the load that hoists of the lifting mechanism of hydraulic hoist;

Locking hold mode: when the lifting mechanism of hydraulic hoist plays load to be raised to certain altitude, because operation needs to make load hover over this height and position, described flexible control loop of hydraulic cylinder stops to oil hydraulic cylinder fuel feeding, and the oil pressure that loads on reverse hydraulic fluid port B generation enters main valve plug spring chamber 7 by damping slot 5, pressure in main valve plug spring chamber 7 and the 6 pretightening force actings in conjunction of main valve plug spring and main valve plug 4 is pressed in and on main valve housing 2, forms conical surface seal, even if damaging also, main valve plug spring 6 can guarantee the reliable realization of its sealing by the oil pressure in main valve plug spring chamber 7, thereby forward hydraulic fluid port A and reverse hydraulic fluid port B are blocked.Simultaneously, now because flexible control loop of hydraulic cylinder stops to oil hydraulic cylinder fuel feeding, there is not oil pressure in pilot control hydraulic fluid port X yet, guide piston 16 under the pretightening force effect of Returnning spring 14 in stroke low order end, the conical seal (contact) face of the cone seal section 140 of guide piston bar 15 coordinates the formation conical surface seal of through hole 20 with the piston rod of guide valve blocks 12, thereby seals the hydraulic oil in main valve plug spring chamber 7.That is to say, the reliable sealing of equilibrium valve entirety makes the rod chamber of oil hydraulic cylinder cannot oil return, load can not be declined under own wt, thereby form locking hold mode.

Decline speed limit state: when oil hydraulic cylinder carries load decline, flexible control loop of hydraulic cylinder is to the rod chamber fuel feeding of oil hydraulic cylinder, rodless cavity is via equilibrium valve oil return of the present invention, now in the rod chamber working oil path of pilot control hydraulic fluid port X due to oil hydraulic cylinder, there is oil pressure, thereby pilot control hydraulic fluid port X sets up oil pressure, while acting on the pressure on guide piston bar 15 in the oil pressure of guide's control port X can overcome the elasticity pretightening force of the Returnning spring acting on guide piston 16 and main valve plug spring chamber 7, guide piston 16, guide piston bar 15 is moved to the left (these three parts can be structure as a whole or after manufacture, interconnect separately) together with pilot spool 8, along with the pressure of pilot control hydraulic fluid port X increases, guide piston 16 displacements increase gradually, guide piston bar 15 is opened with the conical surface seal of guide valve blocks 12, the flow area of the throttling groove on guide piston bar 15 increases gradually along with the movement of guide piston bar 15, now the hydraulic oil in oil hydraulic cylinder rodless cavity acts on the hydraulic oil (oil pressure is P2) main valve plug the second acting surface A2 (example main valve plug right side as shown in Figure 3) from reverse hydraulic fluid port B via damping slot 5, by fixing damping hole 9, be communicated with oil duct 10, piston rod coordinates the throttling groove section 142 of through hole 20 and guide piston bar 15, 143, throttling groove 145 on 144 and drain tap L flow back to fuel tank (or oil return circuit), thereby the oil pressure P2 that acts on the hydraulic oil on main valve plug the second acting surface A2 reduces, after this oil pressure P2 reduces to a certain degree, hydraulic oil (oil pressure is P1) in the rodless cavity of oil hydraulic cylinder (is P2 × A2+Fs after acting on pressure that main valve plug the first acting surface A1 (the pressurized end face of main valve plug 4 as shown in Figure 3 of example in the first acting chamber 3) forms and be greater than the pressure of main valve plug the second acting surface A2 and the pressure of main valve plug spring via reverse hydraulic fluid port B, Fs is the power of main valve plug spring 6), main valve plug moves right, the athletic meeting of main valve plug simultaneously reduces the damping function of damping slot 5, pretending the hydraulic coupling P2 that is used in main valve plug right-hand member increases to some extent, also prevented main valve plug accelerated motion to the right simultaneously, make main valve plug motion comparatively steady, hydraulic oil flows to forward hydraulic fluid port A from reverse hydraulic fluid port B, realize decline function, when carrying load, oil hydraulic cylinder declines when too fast, in the rod chamber of oil hydraulic cylinder, form negative pressure to a certain degree, the oil pressure of pilot control hydraulic fluid port X reduces, thereby the right side motion shown in guide piston bar 15 meeting Fig. 3, the through-current capability of the throttling groove on guide piston bar 15 is reduced, correspondingly make the hydraulic oil P2 in the second acting chamber increase, thereby make main valve plug 4 reduce aperture, avoid declining too fast, play speed limit effect.

On the basis of technique scheme, the present invention also provides a kind of flexible control loop of hydraulic cylinder, this flexible control loop of hydraulic cylinder comprises equilibrium valve and selector valve, known ground, the rod chamber of oil hydraulic cylinder is connected in an actuator port of selector valve via equilibrium valve by a working oil path, rod chamber is connected in another actuator port of selector valve by another working oil path, wherein, this equilibrium valve can adopt the equilibrium valve of technique scheme of the present invention, correspondingly, the forward hydraulic fluid port A of described equilibrium valve is communicated with an actuator port of described selector valve, oppositely hydraulic fluid port B is communicated with the rodless cavity of oil hydraulic cylinder, pilot control hydraulic fluid port X is connected in the rod chamber working oil path of described oil hydraulic cylinder, the L of unloading port is communicated with fuel tank or oil return circuit.At this, it should be noted that, in above-mentioned flexible control loop of hydraulic cylinder, it is only a kind of typical Connecting format that pilot control hydraulic fluid port X is connected in oil hydraulic cylinder rod chamber working oil path, in addition, guide's hydraulic control hydraulic fluid port X of equilibrium valve of the present invention can also be connected in the outside hydraulic control oil sources outside described flexible control loop of hydraulic cylinder, the hydraulic oil that for example oil hydraulic pump pumps is via the rear outside hydraulic control oil sources forming of reduction valve decompression, this outside hydraulic control oil sources can be connected in pilot control hydraulic fluid port X via corresponding hydraulic control oil circuit, on hydraulic control oil circuit, corresponding switch valve or pressure regulator valve etc. can be set, can hydraulic control oil being fed to pilot control hydraulic fluid port X according to working condition, realize above-mentioned control function.The present invention also provides a kind of hydraulic hoist, and this hydraulic hoist comprises above-mentioned flexible control loop of hydraulic cylinder.

By upper description, can be found out, equilibrium valve advantage of the present invention is: first, equilibrium valve of the present invention optionally makes the second acting chamber 17 (the example main valve plug spring chamber 7 that doubles as the second acting chamber as shown in Figure 3) be communicated with fuel tank or oil return circuit by the movement of guide piston bar 15, thereby by controlling the movement of guide piston bar 15, control the movement of main valve plug 4, it adopts pilot control mode, therefore only need the geomery of controlling guide piston bar 7 can easily obtain larger control ratio, this makes the decline Control for Speed Limitation of equilibrium valve sensitiveer, by less control oil pressure, can effectively control the unlatching of main valve plug 3, and the aperture of main valve plug is affected not quite by induced pressure, it depends primarily on the oil pressure at pilot control hydraulic fluid port X place, thereby can not produce frequent shake because of the summary microvariations of induced pressure, better working stability.Second, the second acting chamber 17 can increase through-current capability, reduction damping function damping slot 5 by moving axially along with main valve plug is communicated with reverse hydraulic fluid port B, this can make equilibrium valve control better effects if of the present invention, make to form a kind of relative transient equiliblium between the first acting chamber and the second acting chamber, avoid the aperture of main valve plug excessive.The 3rd, under optimal way, on described guide piston bar 15, be integrated with throttling groove 145, the movement along with guide piston bar 15 when guide's control port X has enough oil pressure of this throttling groove 145 increases aperture gradually, or when reducing, the oil pressure of guide's control port X reduces gradually aperture, therefore stable working is better, has avoided the impact phenomenon in working procedure; The 4th, because this equilibrium valve pilot control is larger, the aperture of equilibrium valve main valve plug is mainly controlled by pilot control oil pressure, simultaneously because the length of throttling groove 145 on guide piston bar can form longlyer, therefore controlled better; The 5th, because required control oil pressure is less, energy-saving effect is better.Apparently, because flexible control loop of hydraulic cylinder of the present invention and hydraulic hoist comprise above-mentioned equilibrium valve of the present invention, therefore it also has above-mentioned technological merit.

Below describe by reference to the accompanying drawings the preferred embodiment of the present invention in detail; but; the present invention is not limited to the detail in above-mentioned mode of execution; within the scope of technical conceive of the present invention; can carry out multiple simple variant to technological scheme of the present invention, these simple variant all belong to protection scope of the present invention.For example, can be integrated valve body by main valve body 1 and guide valve blocks 12, for main valve plug 4, piston rod 15 etc. are installed, this integrated type valve body can be for removably to separation structure.In addition; main valve housing 2 also can with main valve body 1 structure that forms as one, in this case, the structure that main valve housing 2 matches with main valve plug 3 is formed directly on main valve body 1; although than the slightly difficulty of form that adopts main valve housing 2, this mode of texturing also belongs to protection scope of the present invention in processing.In general; equilibrium valve of the present invention has been to propose a kind of more advanced technological scheme; its core technology design is its hydraulic principle; and do not lie in concrete mechanical structure; under the enlightenment of the hydraulic principle shown in Fig. 5; it may occur to persons skilled in the art that various from different shown in Fig. 3 concrete valve mechanisms, but as long as it adopts the technical conceive shown in Fig. 5 of the present invention, it all should be worked as and belong to protection scope of the present invention.

It should be noted that in addition each the concrete technical characteristics described in above-mentioned embodiment, in reconcilable situation, can combine by any suitable mode.For fear of unnecessary repetition, the present invention is to the explanation no longer separately of various possible compound modes.

In addition, also can carry out combination in any between various mode of execution of the present invention, as long as it is without prejudice to thought of the present invention, it should be considered as content disclosed in this invention equally.

Claims (15)

1. equilibrium valve, comprise and there is forward hydraulic fluid port (A) and the main valve body (1) of reverse hydraulic fluid port (B) and the main valve plug (4) that can move in the valve pocket of this main valve body (1), this main valve plug (4) is the normally closed sealing station in described forward hydraulic fluid port (A) and reverse hydraulic fluid port (B) are blocked under the elasticity pretightening force effect of main valve plug spring (6), wherein
Described main valve plug (4) comprises relative the first acting surface (A1) and the second acting surface (A2), this first acting surface (A1) is exposed in the first acting chamber (3) being communicated with described reverse hydraulic fluid port (B), the action direction that is subject to force direction and described elasticity pretightening force of this second acting surface (A2) is identical and be exposed in the second acting chamber (17) being communicated with described reverse hydraulic fluid port (B) via damping slot (5) or damping hole, between the drain tap (L) of this second acting chamber and described equilibrium valve, is provided with draining oil duct (19);
Described equilibrium valve also comprises pilot control module, this pilot control module comprises the guide piston with guide piston bar (15) (16) that can move back and forth, Returnning spring (14) and be positioned at the liquid controling cavity (18) of this guide piston one side, described guide piston bar (15) extend in described draining oil duct (19) and under the effect of described Returnning spring (14) and forms sealing and block this draining oil duct with the inwall of this draining oil duct (19), described liquid controling cavity (18) is communicated with the pilot control hydraulic fluid port (X) of described equilibrium valve, can receive hydraulic control oil and to control described guide piston (16), drive described guide piston bar (15) to move and make described draining oil duct (19) conducting.
2. equilibrium valve according to claim 1, wherein, the main valve plug spring chamber (7) of described main valve plug spring (6) doubles as described the second acting chamber (17).
3. equilibrium valve according to claim 1, wherein, described the second acting chamber (17) is communicated with described reverse hydraulic fluid port (B) by described damping slot (5), this damping slot (5) is formed on the outer circumferential face of described main valve plug (4), and by increase the through-flow aperture of this damping slot (5) in described main valve plug (4) moves away the process of described normally closed sealing station with the coordinating of valve pocket inwall of described main valve body (1).
4. equilibrium valve according to claim 3, wherein, on the valve pocket inner peripheral surface of described main valve body (1), form the projection with axial slope coordinating with described damping slot (5), this projection moves away in the process of described normally closed sealing station with the distance of the diapire of described damping slot (5) and increases at described main valve plug (4), to increase the through-flow aperture of this damping slot (5).
5. equilibrium valve according to claim 1, wherein, the area of described the first acting surface (A1) is less than the area of described the second acting surface (A2).
6. according to the equilibrium valve described in any one in claim 1 to 5, wherein, on described guide piston bar (15), be formed with throttling groove (145), the through-flow aperture of this throttling groove (145) is along with described guide piston bar (15) moves away with the position of the inner wall sealing of described draining oil duct (19) and increases.
7. equilibrium valve according to claim 6, wherein, described draining oil duct (19) comprises that piston rod coordinates through hole (20), and described guide piston bar (15) extend into this piston rod and coordinates in through hole (20) and under the effect of described Returnning spring (14), coordinate through hole (20) to form conical surface seal with described piston rod.
8. equilibrium valve according to claim 7, wherein, described guide piston bar (15) comprises throttling groove section (142, 143, 144), the cross sectional area of this throttling groove section reduces the described throttling groove (145) to increase continuously at the upper formation of described guide piston bar (15) cross sectional area continuously, when described guide piston bar (15) moves away the position that coordinates through hole (20) sealing with described piston rod, described throttling groove section (142, 143, 144) moving through described piston rod coordinates through hole (20) to increase the through-flow aperture of described throttling groove (145).
9. equilibrium valve according to claim 8, wherein, described pilot control module comprises and forms as one with described main valve body (1) or be arranged on the guide valve blocks (12) on this main valve body (1), in this guide valve blocks (12), be formed with the pilot spool chamber (11) and the guide piston chamber that by described piston rod, coordinate through hole (20) to be communicated with, described pilot spool chamber (11) is communicated with described the second acting chamber (17), in described guide piston chamber, be provided with the described guide piston (16) that can slide and be divided into Returnning spring chamber (13) and described liquid controling cavity (18) by this guide piston (16) sealing, in described Returnning spring chamber (13), be provided with described Returnning spring (14), and the chamber wall in this Returnning spring chamber (13) is provided with described drain tap (L).
10. equilibrium valve according to claim 9, wherein, one end part of described guide piston bar (15) is formed as the cone seal section (140) that coordinates through hole (20) to seal mutually with described piston rod, in this cone seal section (140), be formed with and be communicated with oil duct (10), and this cone seal section (140) is connected with the pilot spool (8) being sealed and matched with the inner peripheral surface in described pilot spool chamber (11), in this pilot spool (8), be provided with the fixing damping hole (9) that is communicated with described connection oil duct (10) and the second acting chamber (17), described draining oil duct (19) is by described fixing damping hole (9), be communicated with oil duct (10), piston rod coordinates through hole (20), throttling groove (145) and Returnning spring chamber (13) form.
11. equilibrium valves according to claim 9, wherein, one end part of described guide piston bar (15) is provided with the cone match part (139) that coordinates through hole (20) to seal mutually with described piston rod, this cone match part (139) is positioned at described pilot spool chamber (11) and is fixed to described guide piston bar (15) by locking nut (138) upper, and described draining oil duct (19) coordinates through hole (20), throttling groove (145) and Returnning spring chamber (13) formation by described pilot spool chamber (11), piston rod.
12. equilibrium valves according to claim 9, wherein, one end part of described guide piston bar (15) is connected with or is formed with and is positioned at described pilot spool chamber (11) and the sealing column (137) with the inner peripheral surface interval in this pilot spool chamber (11), sealing post (137) has the conical surface part that coordinates through hole (20) to be sealed and matched with described piston rod, and described draining oil duct (19) coordinates through hole (20), throttling groove (145) and Returnning spring chamber (13) formation by described pilot spool chamber (11), piston rod.
13. equilibrium valves according to claim 6, wherein, in described main valve body (1), be provided with main valve housing (2), the valve pocket of described main valve body (1) forms by this main valve housing (2), and described the first acting chamber (3), the second acting chamber (17) and main valve plug spring chamber (7) formed by described main valve plug (3) and coordinating of this main valve housing (2).
14. flexible control loop of hydraulic cylinders, comprise equilibrium valve and selector valve, wherein, described equilibrium valve is according to the equilibrium valve described in any one in claim 1 to 13, the forward hydraulic fluid port (A) of this equilibrium valve is communicated with an actuator port of described selector valve, oppositely hydraulic fluid port (B) is communicated with the rodless cavity of oil hydraulic cylinder, pilot control hydraulic fluid port (X) is connected in the rod chamber working oil path of described oil hydraulic cylinder or is connected in the outside hydraulic control oil sources outside described flexible control loop of hydraulic cylinder, and drain tap (L) is communicated with fuel tank or oil return circuit.
15. hoists, wherein, this hoist comprises flexible control loop of hydraulic cylinder according to claim 14.
CN201110424886.9A 2011-12-16 2011-12-16 Balanced valve, hydraulic cylinder expansion control loop and crane CN102562699B (en)

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