CN102678645B - Direct-acting overflow valve, direct-acting overflow valve group and hydraulic overflow loop - Google Patents
Direct-acting overflow valve, direct-acting overflow valve group and hydraulic overflow loop Download PDFInfo
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- CN102678645B CN102678645B CN201210175068.4A CN201210175068A CN102678645B CN 102678645 B CN102678645 B CN 102678645B CN 201210175068 A CN201210175068 A CN 201210175068A CN 102678645 B CN102678645 B CN 102678645B
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Abstract
The invention discloses a direct-acting overflow valve, comprising a remote control opening (V) and a hydraulic oil counteractive cavity (X) communicated with the remote control opening (V), wherein the hydraulic oil counteractive cavity (X) is communicated with an oil inlet (P); the hydraulic oil in the hydraulic oil counteractive cavity (X) acts on a valve core (102) in the same direction as the spring acts on a valve core (10); the hydraulic oil on an oil inlet pressure surface has an effective area more than the hydraulic oil on the pressure surface of the valve core (102) exposed in the hydraulic oil counteractive cavity (X). Additionally, the invention also provides a direct-acting overflow valve group comprising the direct-acting overflow valve, and a hydraulic overflow loop. As the remote control opening is added in the direct-acting overflow valve, the direct-acting overflow valve has an unloading function. Meanwhile, with the adoption of the direct-acting overflow valve, the functions of overflowing with low flow and unloading with high flow are realized when the overflowing and unloading functions are realized due to the more optimized structural design.
Description
Technical field
The present invention relates to a kind of relief valve, particularly, relate to a kind of direct-acting overflow valve.In addition, the invention still further relates to a kind of direct-acting overflow valve valve group and hydraulic overflow loop that comprises described direct-acting overflow valve.
Background technique
Relief valve is a kind of conventional hydraulic control valve in hydraulic system, it can be used for controlling on main oil way of hydraulic system the maximum pressure of hydraulic system, also on can for example, working oil path for certain hydraulic actuator (oil hydraulic cylinder), to control the working pressure of this actuator.Relief valve is mainly divided into direct-acting overflow valve and pilot operated compound relief valve, wherein direct-acting overflow valve has simple in structure, processing cost is lower, the advantage such as be active in one's movements, but existing direct-acting overflow valve structure due to self in application has some limitations.
Particularly, for the sake of security, the relief valve of band remote control mouth (those skilled in the art are also referred to as " remote control orifice ") is all installed in most of hydraulic systems of engineering machinery, generally by the hydraulic oil pressure of electromagnetic valve remote control mouth.For example, the arm of truck crane is with respect to the horizontal plane when less angle, and arm position of centre of gravity and pivoting support centre distance are far away, and hoist is to the arm direction trend grow that topples.If operator carry out luffing operation; when the angle of arm direction and horizontal plane is less than setting value and is dangerous; controller can send the remote control mouth decompression of secondary relief valve that electrical signal makes the corresponding filler opening of luffing selector valve; and then make secondary relief valve in unloading condition (gushing the hydraulic oil in working oil path), realize safety protection effect.
But the relief valve that can play Unloading Effect with remote control mouth is all pilot operated compound relief valve conventionally, Fig. 1 is for typically with the pilot operated compound relief valve of remote control mouth.As shown in Figure 1, when traditional pilot operated compound relief valve with remote control mouth plays Unloading Effect, remote control mouth V decompression, thereby main valve plug spring chamber decompression, the oil pressure of oil inlet P overcomes spring force promotion main valve plug and realizes Unloading Effect.When realizing overflow effect and Unloading Effect, its main valve plug all can move to limit position, that is to say that when overflow with the opening of its main valve plug when the off-load be the same.When off-load, if the hydraulic oil in assurance working oil path can be laid down completely, the opening of main valve plug must be enough large so.This also causes the opening of main valve plug when overflow can be larger.When this relief valve is arranged on, plays level pressure do the used time in working oil path, if working pressure reaches setting pressure, have more oil spill stream, the flow in working oil path also can reduce.Can cause like this movement speed of actuator slack-off, system heating, Efficiency Decreasing.Meanwhile, known ground, the structure of pilot operated compound relief valve is comparatively complicated, and processing cost is higher, and can there is certain retardation phenomenon in speed of response simultaneously.
Chinese utility model patent application CN2086355U discloses the moving relief valve of a kind of differential pressure direct, Figure 2 shows that the disclosed differential pressure direct of this utility application moves relief valve, at this, it is to be noted, the moving relief valve of this differential pressure direct does not only have remote control mouth, without unloading function, and from hydraulic principle, analyze even its basic relief function and also cannot realize, shown in Figure 2, the moving relief valve of this differential pressure direct is by the common valve internal pressure chamber that forms of pressure balance valve pocket 13 and spool 10, and by being formed on throttle orifice on spool 10, described internal pressure chamber is communicated with the inlet opening 19 of relief valve, there is area difference in the hydraulic oil active area that all the hydraulic oil active area of upper-end surface of not mentioned spool 10 in described valve internal pressure chamber and the hydraulic oil of inlet opening 19 act on the lower end conical surface of spool 10 in the full text of this application file, from the concrete structure shown in Fig. 2, can only think that the hydraulic oil active area of upper-end surface of spool 10 and the hydraulic oil active area of the lower end conical surface of spool 10 equate, in this case, incompressibility due to hydraulic oil, when in inlet opening, oil pressure moment of 19 hydraulic oil increases, spool 10 has the trend moving upward, hydraulic oil moment in described valve internal pressure chamber is compressed, the oil pressure of the hydraulic oil in it also can rise moment, because the hydraulic oil active area of upper-end surface of spool 10 and the hydraulic oil active area of the lower end conical surface of spool 10 equate, therefore the oil pressure of the hydraulic oil in described valve internal pressure chamber only needs the oil pressure rising to 19 places, inlet opening to equate, just the suffered thrust in lower end surface that can balance valve core 10, oil pressure due to described valve internal pressure chamber equates with the oil pressure at 10 places, inlet opening in this case, therefore the hydraulic oil in valve internal pressure chamber can't be via 19 backflows to inlet opening of the throttle orifice on spool 10.Therefore, only from the disclosed technology contents of this utility application CN2086355U, the moving relief valve of this differential pressure direct is generally speaking actual is rigidity, and it can not realize differential pressure relief function, more can not be via the existing unloading function of remote control cause for gossip.
In view of this, need to design a kind of novel direct-acting overflow valve, so that this direct-acting overflow valve has the unloading function via remote control mouth, thereby widen the application area of direct-acting overflow valve.
Summary of the invention
Technical problem to be solved by this invention is to provide a kind of direct-acting overflow valve, and this direct-acting overflow valve not only can be realized relief function effectively, and can be used in and realize unloading function.
Further, technical problem to be solved by this invention is to provide a kind of direct-acting overflow valve, and this direct-acting overflow valve not only can be used in realizes unloading function, and can realize large flow off-load, small flow overflow.
The technical problem that the present invention also will solve is to provide a kind of direct-acting overflow valve valve group, and this direct-acting overflow valve group not only can realize relief function effectively, and can realize unloading function.
In addition, this invention technical problem to be solved is to provide a kind of hydraulic overflow loop, and relief function not only can be realized effectively in this hydraulic overflow loop, and can realize unloading function.
In order to solve the problems of the technologies described above, the invention provides a kind of direct-acting overflow valve, comprise the valve body with filler opening and return opening, spool and the spring that this spool is biased into normality sealing station, described spool has oil-feed pressure-bearing surface, the hydraulic oil of described filler opening input can act on the resistance that overcomes spring on this oil-feed pressure-bearing surface to promote spool and move and realize overflow, wherein, described direct-acting overflow valve also comprises remote control mouth and the hydraulic oil reaction chamber being communicated with this remote control mouth, this hydraulic oil reaction chamber is communicated with filler opening, hydraulic oil in described hydraulic oil reaction chamber is identical with the force direction of described spring to the force direction of this spool, and the hydraulic oil effective active area of described oil-feed pressure-bearing surface is greater than the hydraulic oil effective active area of the compression face that is exposed to hydraulic oil reaction chamber of described spool, so that the active force that the driving spool that the hydraulic oil of identical oil pressure forms described oil-feed pressure-bearing surface moves is greater than the active force that the prevention spool of described compression face formation is moved.
In order to realize large flow off-load, small flow overflow, preferably, the outer circumferential face of described spool is sliding combined with piston, and the inner peripheral surface of the outer circumferential face of this piston and the valve pocket of described valve body is slidably matched, one end end face of described piston is exposed to described hydraulic oil reaction chamber, other end is formed on the first ladder stop surface on the valve pocket inwall of described valve body and protrudes and is formed on the second ladder stop surface on described spool outer circumferential face towards protrusion, contacting with the second ladder stop surface with this first ladder stop surface, at described spool during in described normality sealing station, distance between described the first ladder stop surface and the other end of described spool is less than the distance between described the second ladder stop surface and the other end of this spool.
Preferably, the spring chamber of described direct-acting overflow valve doubles as described hydraulic oil reaction chamber.
Typically, described filler opening and described spring chamber lay respectively at the opposite end of described spool, and the oil-feed pressure-bearing surface of described spool is exposed in described filler opening.
Particularly, one end of described spool extend in described spring chamber, the end that extend into described spring chamber of this spool is formed with spring seat location ladder surface and the first spring seat is installed, and this first spring seat is orientated the end face space that is exposed to described spring chamber of the end face towards described piston and the described piston that make this first spring seat as by described spring seat location ladder surface.
Particularly, second spring seat relative with described the first spring seat is also installed in described spring chamber, an end in contact of this second spring seat and screw press, this screw press screw thread is arranged on for sealing the plug of described spring chamber.
More specifically, described spring comprises the first spring and be positioned at this first spring inner and second spring coaxial with this first spring, and the two ends of the two ends of this first spring and the second spring are set to respectively on described the first spring seat and the second spring seat.
Selectively, described spring comprises the first spring and the second spring, the two ends of described the first spring are set to respectively on described the first spring seat and the second spring seat, described the second spring supporting is between the end face and the supporting lip on described spool of the described spring chamber dorsad of described piston, described the first spring seat is threaded onto on described spool, to make this second spring form pretightening force via the second spring described in described piston compression.
Preferably, on described plug, be formed with the ring week stop lug of stretching out in described spring chamber, this encircles all stop lug corresponding to the fringe region of described piston end surface, to encircle all stop lug with this at this piston when described spring chamber moves to precalculated position, contacts.
Preferably, described hydraulic oil reaction chamber is communicated with described filler opening by the damping hole being formed on described spool.
Particularly, on described valve body, valve pocket is installed, described hydraulic control interruption-forming, on described valve pocket, and is communicated with described hydraulic oil reaction chamber by the inside oil duct being formed on this valve pocket and valve body.
On the basis of the technological scheme of above-mentioned direct-acting overflow valve, the present invention also provides a kind of direct-acting overflow valve valve group, comprise direct-acting overflow valve, wherein, described direct-acting overflow valve is the direct-acting overflow valve described in above-mentioned arbitrary technological scheme, and the remote control mouth of this direct-acting overflow valve is connected in return opening or the fuel tank of this direct-acting overflow valve via on-off control valve.
Specifically selectively, described on-off control valve is bi-bit bi-pass solenoid directional control valve.
In addition, the present invention also provides a kind of hydraulic overflow loop, and wherein, this hydraulic overflow loop comprises above-mentioned direct-acting overflow valve valve group, and the filler opening of described direct-acting overflow valve is communicated with the working connection of hydraulic system or working oil path, and return opening is communicated with fuel tank.
Pass through technique scheme, direct-acting overflow valve of the present invention has increased hydraulic oil reaction chamber and remote control mouth, and by making the hydraulic oil effective active area of oil-feed pressure-bearing surface be greater than the hydraulic oil effective active area that this spool is exposed to the compression face in described hydraulic oil reaction chamber, thereby guaranteed the realization of relief function, by remote control mouth, optionally make hydraulic oil reaction chamber draining decompression simultaneously, can make direct-acting overflow valve effectively realize unloading function, simultaneously, because hydraulic oil reaction chamber is identical with the force direction of spring to the force direction of spool, therefore direct-acting overflow valve of the present invention can be selected the spring that elasticity coefficient is less, make the overall operation of relief valve comparatively light, and kept direct-acting overflow valve simple in structure, responding fast, the advantages such as processing cost is lower.In addition, in further preferred implementation, the present invention is by the cooperation of piston, the first ladder stop surface and the second ladder stop surface, effectively when realizing overflow effect and Unloading Effect, valve core opening is varied in size, thereby realized the function of " small flow overflow, large flow off-load ".
Other features and advantages of the present invention partly in detail are described the embodiment subsequently.
Accompanying drawing explanation
Following accompanying drawing is used to provide a further understanding of the present invention, and forms a part for 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 is typically with the sectional structure schematic diagram of the pilot operated compound relief valve of remote control mouth in prior art.
Fig. 2 is the sectional structure schematic diagram of the moving relief valve of disclosed differential pressure direct in Chinese utility model patent application CN2086355U.
Fig. 3 is the hydraulic schematic diagram of the direct-acting overflow valve of the specific embodiment of the invention, and wherein the remote control mouth of this direct-acting overflow valve is connected with bi-bit bi-pass solenoid directional control valve.
Fig. 4 is the sectional structure schematic diagram of the direct-acting overflow valve of the specific embodiment of the invention, the wherein said direct-acting overflow valve rest position that is in the normal state.
Fig. 5 is the sectional structure schematic diagram of the direct-acting overflow valve of the specific embodiment of the invention, and wherein said direct-acting overflow valve is in overflow position.
Fig. 6 is the sectional structure schematic diagram of the direct-acting overflow valve of the specific embodiment of the invention, and wherein said direct-acting overflow valve is in unloading condition.
Fig. 7 is the sectional structure schematic diagram of the direct-acting overflow valve of a kind of modification mode of execution of the present invention.
Fig. 8 is the sectional structure schematic diagram of the direct-acting overflow valve of the another kind of modification mode of execution of the present invention.
Description of reference numerals:
1 direct-acting overflow valve; 2 bi-bit bi-pass solenoid directional control valves;
101 valve bodies; 102 spools;
103 pistons; 104 valve pockets;
105 plugs; 106 screw press;
107 locknuts; 108 first spring seats;
109 first springs; 110 second springs;
111 second spring seats; 112 first ladder stop surfaces;
113 second ladder stop surfaces; The all stop lug of 114 ring;
115 supporting lips; X hydraulic oil reaction chamber;
Y spring chamber; P filler opening;
PA oil-feed pressure-bearing surface; T return opening;
V remote control mouth.
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.
Fig. 3 to Fig. 6 shows a kind of embodiment of direct-acting overflow valve of the present invention, the formula that needs explanation, shown in Fig. 3 to Fig. 6, be only the preferred structure of direct-acting overflow valve of the present invention, the technical conceive of direct-acting overflow valve of the present invention is not limited to the detail showing in figure.In addition, in explanation below, except special instruction connected relation, corresponding chambers should keep sealing or sealing substantially, to avoid existing the oily phenomenon of string.
With reference to Fig. 3 to Fig. 6, direct-acting overflow valve of the present invention comprises the valve body 101 with oil inlet P and oil return inlet T, be slidably fitted in the spool 102 in the valve pocket of this valve body 101 and the spring that this spool 102 is biased into normality sealing station, spool 102 has oil-feed pressure-bearing surface PA, at this, it should be noted that, this oil-feed pressure-bearing surface PA directly can directly be exposed in oil inlet P in oil inlet P when one end of spool 102 forms, but for those skilled in the art apparently, oil inlet P also can be communicated to by inner oil-feed oil duct the oil suction chamber of spool 102 one end, now the oil-feed pressure-bearing surface PA of spool 102 is exposed in oil suction chamber.For relief valve, the hydraulic oil of oil inlet P input can act on this oil-feed pressure-bearing surface PA when reaching the cracking pressure of relief valve, thereby promote resistance that spool 102 overcomes spring to move and realize overflow, wherein, direct-acting overflow valve of the present invention also comprises remote control mouth V and the hydraulic oil reaction chamber X being communicated with this remote control mouth V, in Fig. 4, the spring chamber Y of relief valve doubles as hydraulic oil reaction chamber X, but for those skilled in the art apparently, by simple malformation, hydraulic oil reaction chamber also can independently form, and be not limited to the details of Fig. 4.
As shown in Figure 4, the spring chamber Y that doubles as hydraulic oil reaction chamber X is communicated with described oil inlet P, typically by the damping hole being axially formed on spool 102, be communicated with, can certainly be communicated with by the inside oil duct being formed on valve body 101, hydraulic oil reaction chamber X is generally relatively little with the cross-sectional flow area that is communicated with oil duct of oil inlet P, this is mainly can release rapidly the hydraulic oil in hydraulic oil reaction chamber by remote control mouth V while considering off-load, guarantees rapid off-load.
Hydraulic oil in described hydraulic oil reaction chamber X is identical with the force direction of described spring to the force direction of spool 102, and described oil-feed pressure-bearing surface PA " hydraulic oil effective active area " is greater than " the hydraulic oil effective active area " of the compression face of the described hydraulic oil reaction chamber X of being exposed to of described spool 102.At this, it should be noted that, as mentioned above, hydraulic oil reaction chamber X is not limited to the structural type that the spring chamber Y shown in Fig. 4 doubles as hydraulic oil reaction chamber X, within the scope of technical conceive of the present invention, hydraulic oil reaction chamber X can form separate chamber, in this case, spool 102 exposes the anti-compression face of doing in the X of chamber of hydraulic oil and can exist a plurality of, thereby the hydraulic oil in described hydraulic oil reaction chamber X can be generally hydraulic oil to the active force of each compression face to the active force of spool 102 effect on spool movement direction (be spool axially) is made a concerted effort.In addition, the oil-feed pressure-bearing surface PA at oil inlet P place is also not limited to form the situation of single oil-feed pressure-bearing surface PA.
In general, no matter quantity or the shape of the oil-feed pressure-bearing surface PA of spool 102 and the compression face that is exposed to hydraulic oil reaction chamber X of spool 102, as long as the active force that the driving spool 102 that the hydraulic oil active area of oil-feed pressure-bearing surface PA of spool 102 and the hydraulic oil active area of the compression face that is exposed to hydraulic oil reaction chamber X of spool 102 is formed make the hydraulic oil of identical oil pressure to form oil-feed pressure-bearing surface PA moves is greater than the active force that prevention spool 102 that described compression face is formed moves, that is to say, as long as make the hydraulic oil effective active area of described oil-feed pressure-bearing surface PA be greater than the hydraulic oil effective active area of the compression face of the described hydraulic oil reaction chamber X of being exposed to of described spool 102, can realize the correlation of above-mentioned active force.Particularly, because the hydraulic oil acting surface on spool 102 might not be perpendicular to the movement direction of spool 102, just there is the situation of the conical surface in example oil-feed pressure-bearing surface PA as shown in Figure 4, and in some hydraulic fluid ports or oil pocket, there is the problem that also exists active force to cancel out each other under the situation of a plurality of hydraulic oil acting surfaces, therefore in hydraulic efficiency slide valve field, those skilled in the art represent the corresponding hydraulic fluid port of spool or the area relationship between the hydraulic oil acting surface in oil pocket by the term of " hydraulic oil effective active area " conventionally, its concrete meaning is as follows: the hydraulic oil of a certain oil pressure acts on each hydraulic oil acting surface of a certain oil pocket of being exposed to of spool or hydraulic fluid port, thereby be formed for driving spool to move or stop the active force (refer to overall effect make a concerted effort) of a certain numerical value that spool moves under the situation that has a plurality of hydraulic oil acting surfaces, the active force of this numerical value is " hydraulic oil effective active area " divided by the oil pressure of above-mentioned hydraulic oil, this " hydraulic oil effective active area " comes from oil pressure and is multiplied by the well-known formula that active area equals hydraulic action, at spool movement direction under definite situation, each hydraulic oil acting surface that is exposed to a certain oil pocket or hydraulic fluid port of spool need to be converted into along spool movement direction area of contour in the plane perpendicular to spool movement direction and calculate, and the area of contour of each hydraulic oil acting surface needs to have according to the force direction bearing the problem of offsetting or being added, therefore " hydraulic oil effective active area " can be by projecting to each hydraulic oil acting surface of a certain oil pocket of being exposed to of spool or hydraulic fluid port in the plane perpendicular to spool movement direction along spool movement direction, and and then according to the being subject to force direction of each hydraulic oil acting surface, carry out the addition of area of contour or offset to calculate obtain, but and consistent with the real area of hydraulic oil acting surface scarcely, the situation that for example in Fig. 4, oil-feed pressure-bearing surface PA comprises the conical surface.The conversion of the hydraulic oil effective active area of relevant valve core of the spool valve in each hydraulic fluid port or oil pocket is who knows for those skilled in the art, does not repeat them here.
In above-mentioned embodiment, direct-acting overflow valve of the present invention has increased hydraulic oil reaction chamber and remote control mouth V, and by making the hydraulic oil effective active area of oil-feed pressure-bearing surface PA be greater than the hydraulic oil effective active area that spool 102 is exposed to the compression face in described hydraulic oil reaction chamber X, when oil inlet P oil-feed, when the hydraulic fluid pressure of oil inlet P arrives predetermined value, although the oil pressure in now hydraulic oil reaction chamber X is identical with the oil pressure at oil inlet P place, but because being greater than spool 102, the area of oil-feed pressure-bearing surface PA is exposed to the hydraulic oil active area in described hydraulic oil reaction chamber X, correspondingly the hydraulic oil at oil inlet P place is greater than hydraulic oil in the hydraulic oil reaction chamber X thrust to spool 102 to the thrust of spool 102, once the difference of both thrust is greater than the pretightening force of spring, just can promote spool 102 and leave normality sealing station, the volume of now hydraulic oil reaction chamber X diminishes, oil pressure in hydraulic oil reaction chamber X increases rapidly, make the hydraulic oil in hydraulic oil reaction chamber X for example, by the circulation oil duct (damping hole) between oil inlet P and hydraulic oil reaction chamber X, to be back to oil inlet P, thereby guaranteed the realization of relief function, by remote control mouth V, optionally make hydraulic oil reaction chamber draining X decompression simultaneously, can make direct-acting overflow valve effectively realize unloading function, in addition, because hydraulic oil reaction chamber is identical with the force direction of spring to the force direction of spool, therefore direct-acting overflow valve of the present invention can be selected the spring that elasticity coefficient is less, make the overall operation of relief valve comparatively light, and kept direct-acting overflow valve simple in structure, responding fast, the advantages such as processing cost is lower.
In order to realize large flow off-load, the function of small flow overflow, shown in Fig. 4 and Fig. 6, it can be generally the Spielpassung that can form relative sliding that the outer circumferential face of described spool 102 is sliding combined with piston 103(, and keep sealing), and it (can be generally the Spielpassung that can form relative sliding that the inner peripheral surface of the valve pocket of the outer circumferential face of this piston 103 and valve body 101 is slidably matched, and keep sealing), one end end face of piston 103 is exposed to for example spring chamber Y in Fig. 4 of described hydraulic oil reaction chamber X(), other end is formed on the first ladder stop surface 112 on the valve pocket inwall of valve body 101 and protrudes and is formed on the second ladder stop surface 113 on described spool 102 outer circumferential faces towards protrusion, with (the hydraulic oil reaction chamber X dorsad of the other end at piston 103 this piston during by the promotion of the hydraulic fluid pressure in hydraulic oil reaction chamber X, spring chamber Y for example) contact with this first ladder stop surface 112, and when being promoted by the hydraulic fluid pressure of oil inlet P, spool 102 make this second ladder stop surface (113) contact with the other end of this piston, at described spool during in described normality sealing station, distance between described the first ladder stop surface 112 and the other end of described spool 102 is less than the distance between described the second ladder stop surface 113 and the other end of this spool 102.
Referring to Fig. 4, typically, described oil inlet P and described spring chamber Y lay respectively at the opposite end of spool 102, and the oil-feed pressure-bearing surface PA of described spool 102 is exposed in described oil inlet P.At spring chamber Y, double as under the situation of hydraulic oil reaction chamber X, one end of spool 102 extend in spring chamber Y, the end that extend into spring chamber Y of this spool 102 is formed with spring seat location ladder surface and the first spring seat 108 is installed, this first spring seat 108 is orientated the end face space that is exposed to spring chamber Y of the end face towards piston 103 and the piston 103 that make this first spring seat 108 as by described spring seat location ladder surface, avoid the first spring seat to increase the hydraulic oil active area of spool in spring chamber when this is main.Second spring seat 111 relative with described the first spring seat 108 is also installed in described spring chamber Y, one end in contact of this second spring seat 111 and screw press 106, these screw press 106 screw threads are arranged on for sealing the plug 105 of described spring chamber Y, and the other end of screw press 106 is generally fastening by locknut 107 lockings.Plug 105 generally can be installed on valve body 101 by the outside thread of its outer circumferential face.
In direct-acting overflow valve of the present invention, above-mentioned spring can adopt a spring with the same in conventional relief valve, but in order to make the operation of relief valve more steadily reliable, preferably, shown in Figure 4, described spring comprises the first spring 109 and is positioned at inner and second springs 110 coaxial with this first spring 109 of this first spring 109, and the two ends of the two ends of this first spring 109 and the second spring 110 are set to respectively on the first spring seat 108 and the second spring seat 111.
A kind of modification mode of execution as spring, shown in Figure 7, at spring described in this variant, still can comprise the first spring 109 and the second spring 110, wherein only the first spring (109) is arranged in spring chamber Y, the two ends of this first spring are set to respectively on the first spring seat 108 and the second spring seat 111, the second spring 110 is supported between the end face and the supporting lip 115 on spool 102 of the Y of spring chamber dorsad of piston 103, the first spring seat 108 is threaded onto on spool 102, to make this second spring 110 form pretightening force via described piston 103 compression the second springs 110.
On the basis of above-mentioned mode of execution, in order to form spacing to piston 103 at direct-acting overflow valve of the present invention during in off-load, as a kind of optimal way, shown in Figure 8, on described plug 105, be formed with the ring week stop lug 114 of stretching out in described spring chamber Y, this encircles all stop lug 114 corresponding to the fringe region of piston 103 end faces, to encircle all stop lug 114 with this at this piston 103 when described spring chamber Y moves to precalculated position, contact, thereby the motion of piston 103 is formed to position-limiting action.
In addition, shown in Figure 4, particularly, on described valve body 101, valve pocket 104 is installed, described hydraulic control mouth V-arrangement becomes on valve pocket 104, and is communicated with hydraulic oil reaction chamber X by the inside oil duct being formed on this valve pocket 104 and valve body 101.
On the basis of the technological scheme of above-mentioned direct-acting overflow valve, referring to Fig. 3, the present invention also provides a kind of direct-acting overflow valve valve group, comprise direct-acting overflow valve, wherein, described direct-acting overflow valve is the direct-acting overflow valve described in technique scheme, and the remote control mouth V of this direct-acting overflow valve is connected in oil return inlet T or the fuel tank of this direct-acting overflow valve via on-off control valve.Typically, on-off control valve is bi-bit bi-pass solenoid directional control valve 2, certainly to those skilled in the art, on-off control valve can also adopt the control valve of other type, such as bi-bit bi-pass hand-operated direction valve, switch valve etc., as long as can realize the oil return inlet T of remote control mouth V and direct-acting overflow valve or the break-make of the oil circuit between fuel tank.
In addition, the present invention also provides a kind of hydraulic overflow loop, and wherein, this hydraulic overflow loop comprises above-mentioned direct-acting overflow valve valve group, and the filler opening T of described direct-acting overflow valve is communicated with working connection or the working oil path of hydraulic system, and oil return inlet T is communicated with fuel tank.
Referring to the preferred implementation shown in Fig. 3 to Fig. 8, describe the working principle of direct-acting overflow valve of the present invention, it should be noted that protection scope of the present invention is not limited to the detail shown in Fig. 3 to Fig. 8.
Shown in Figure 3, the remote control mouth V of direct-acting overflow valve of the present invention is connected with a bi-bit bi-pass solenoid directional control valve, and its Main Function is to control remote control mouth V be communicated with fuel tank or block, so that double as spring chamber Y release or the pressurize of hydraulic oil reaction chamber X.
Shown in Figure 4, when relief valve is not worked or the oil pressure of oil inlet P during lower than setting pressure, the first spring seat 108 is against on spool 102, because the conical surface of the effect spool 102 of spring force contacts with the seamed edge of valve body 101 inner chambers, thereby formation linear sealing, cuts off oil inlet P and oil return inlet T mouth mutually.In order to guarantee that spring force can act on spool 102 completely, between piston 103 and the first spring seat 108, remain with certain free gap, this spring seat location ladder surface extending on the end in spring chamber Y by spool 102 is realized.The inner peripheral surface of the outer circumferential face of spool 102 and piston 103 forms the Spielpassung that can slide and seal, and one section of inner peripheral surface of the valve pocket of the outer circumferential face of piston 103 and valve body 101 forms the Spielpassung that can slide and seal.The Main Function of this two places Spielpassung is to guarantee that again piston 103 and spool 102 can move when spring chamber Y is cut off mutually with oil return inlet T mouth.On spool 102, having damping hole makes oil inlet P be connected with spring chamber Y.In addition the spring chamber Y that, doubles as hydraulic oil reaction chamber X is connected with remote control mouth V.
Its working principle is as follows:
The first, relief function: as shown in Figure 3 and Figure 5.Oil inlet P oil-feed, and bi-bit bi-pass solenoid directional control valve 2 dead electricity.Due to bi-bit bi-pass solenoid directional control valve 2 dead electricity, so remote control mouth V is different from fuel tank, the hydraulic fluid pressure in spring chamber Y is kept, and, when oil inlet P oil-feed, the oil pressure of oil inlet P equates with the oil pressure of spring chamber Y.In this state, the hydraulic oil of oil inlet P to the active force of spool 102 to the right, in the embodiment shown in Fig. 4, the sectional area that the hydraulic oil effective active area of the oil-feed pressure-bearing surface PA of spool 102 is oil inlet P deducts the sectional area of the damping hole in spool 102, the active force that the hydraulic oil of spring chamber Y can produce left spool 102 simultaneously, the hydraulic oil effective active area of the compression face that is exposed to this spring chamber of spool 102 is the section area (note: owing to having gap between piston 103 and the first spring seat 108 that the sectional area (equating with the sectional area of the endoporus of piston 103) of the spool part that piston 103 is installed of spool 102 deducts spool 102 internal damping holes, therefore the pressure bearing on the first spring seat 108 can be cancelled out each other, thereby the sectional area of the spool part that piston 103 is installed that hydraulic oil effective active area is spool deducts the sectional area of the damping hole in spool 102).Because the sectional area of oil inlet P is greater than the sectional area of the spool part that piston 103 is installed of spool, also that is to say, spring chamber Y(this spring chamber Y in illustrated optimal way that is exposed to that the hydraulic oil effective active area corresponding to oil-feed pressure-bearing surface PA of spool is greater than spool 102 doubles as hydraulic oil reaction chamber X) in the hydraulic oil effective active area of compression face, therefore above-mentioned two power make a concerted effort be level to the right, and increase along with the increase of oil inlet P oil pressure.When the oil pressure of oil inlet P increases to a certain degree, to the active force of spool 102, will overcome spring force promotion spool 102 and move right.Because piston 103 is also subject to the active force left of spring chamber Y, thereby the left side of piston 103 is against on the first ladder stop surface 112 of valve body 101.So when relief valve during in overflow the stroke of spool 102 can be limited by piston, opening is smaller, thereby realizes the overflow of small flow.
The second, unloading function: as shown in Figure 3 and Figure 6, and oil inlet P oil-feed, bi-bit bi-pass solenoid directional control valve 2 obtains electric.Now, because bi-bit bi-pass solenoid directional control valve 2 must be electric, remote control mouth V communicates with oil return T, so spring chamber Y decompression.So, when oil inlet P oil-feed, the active force that hydraulic oil produces to the right spool 102, the active force that the first spring 109 and 110 pairs of spools of the second spring 102 produce left.Because the hydraulic oil effective active area of the oil-feed pressure-bearing surface PA of oil inlet P place spool is larger, and spring force a little less than, so just can overcome spring force promotion spool 102 in the situation that oil inlet P pressure is lower moves right, spool 102 also can drive piston 103 to move right by the second ladder stop surface 113 on spool 102, the opening of spool 102 can be relatively large like this, realized large flow off-load.When spool 102 reaches balance, the pressure of oil inlet P and spring force balance.By the design to spring, can be so that oil inlet P only maintains lower pressure.That is to say, when remote control mouth V is communicated with fuel tank and during release, this direct-acting overflow valve can make working oil path off-load, only has in working oil path to form lower back pressure by spring, is not enough to overcome load.
In addition, as mentioned above, the present invention is not limited to the embodiment shown in Fig. 3 to Fig. 6, for example, referring to Fig. 7, by changing the mounting point of the second spring 110, also can realize identical function.In this replacement scheme, changed the mounting point of the second spring 110.The first spring seat 108 is preferably threaded connection with spool 102, while making the second spring 110 between spool 102 and piston 103, can remain precompressed.When bi-bit bi-pass solenoid directional control valve 2 dead electricity, remote control mouth V pressurize, during oil inlet P oil-feed, spring chamber Y pressure is identical with oil inlet P pressure, as mentioned above, because the hydraulic oil effective active area of the oil-feed pressure-bearing surface PA of oil inlet P place spool is greater than the hydraulic oil effective active area that is exposed to the compression face in spring chamber Y of spool 102, so the making a concerted effort for active force to the right of this two power.Now, piston 103 is doubled as pressure-acting pushing and pressing that the hydraulic oil of the spring chamber Y of hydraulic oil reaction chamber X produces on valve body 101 (also make thus piston 103 and the first spring seat 109 spaced apart), and the active force of 110 pairs of spools 102 of the second spring is axial forces left.When the hydraulic oil at oil inlet P place acts on active force on oil-feed pressure-bearing surface PA and is greater than hydraulic oil in the first spring 109, the second spring 110 and spring chamber Y to the making a concerted effort of spool active force, spool is opened, relief valve overflow.When solenoid valve obtain electric, remote control mouth V decompression, during oil inlet P oil-feed, spool 102, piston 103, the second spring 110 and the first spring seat 108, under the effect of the hydraulic oil of oil inlet P, overcome the spring force of spring I 109, realize Unloading Effect.In this replacement scheme, the second spring 110 is compressed all the time, and the precompression of the second spring 110 is the minimum set pressure of this relief valve when overflow.And the oil pressure relief minimum of relief valve can be adjusted to zero in the technological scheme shown in Fig. 4, spring, without precompressed, also just can not be realized overflow effect certainly in this case.
In addition, by the structure changing with externally threaded plug 105, also can realize identical function.In this replacement scheme, changed the structure of plug 105.When off-load, all stop lug 114 of the ring stretching out in described spring chamber Y of plug 105 can limit the stroke of piston 103, thus the opening of restriction spool 102.
By upper description, can be found out, the invention has the advantages that: direct-acting overflow valve of the present invention has increased hydraulic oil reaction chamber X(and for example doubled as the spring chamber Y of hydraulic oil reaction chamber X in Fig. 4) and remote control mouth V, and be exposed to the hydraulic oil active area in described hydraulic oil reaction chamber X by making the hydraulic oil effective active area of oil-feed pressure-bearing surface PA be greater than this spool, thereby guaranteed the realization of relief function, by remote control mouth V, optionally make hydraulic oil reaction chamber X draining decompression simultaneously, can make direct-acting overflow valve effectively realize unloading function, simultaneously, because hydraulic oil reaction chamber X is identical with the force direction of spring to the force direction of spool 102, therefore direct-acting overflow valve of the present invention can be selected the spring that elasticity coefficient is less, make the overall operation of relief valve comparatively light, and kept direct-acting overflow valve simple in structure, responding fast, the advantages such as processing cost is lower.In addition, in further preferred implementation, the present invention is by the cooperation of piston 103, the first ladder stop surface 112 and the second ladder stop surface 113, effectively when realizing overflow effect and Unloading Effect, valve core opening is varied in size, thereby realized the function of " small flow overflow, large flow off-load ".That is to say, the present invention by having increased remote control mouth on direct-acting overflow valve, and be exposed to the hydraulic oil active area in described hydraulic oil reaction chamber X by making the hydraulic oil effective active area of oil-feed pressure-bearing surface PA of the spool at oil inlet P place be greater than this spool, thereby make direct-acting overflow valve also with unloading function, and preferably when realizing overflow effect and Unloading Effect, valve core opening varies in size, realized the function of " the large flow off-load of small flow overflow ", it is compared with traditional direct-acting overflow valve, it can realize unloading function effectively by remote control mouth, compare with traditional pilot operated compound relief valve with remote control, it is simple in structure, be easier to installation and maintenance.Therefore, direct-acting overflow valve of the present invention has the advantage of direct-acting overflow valve and pilot operated compound relief valve concurrently
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.
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, between various mode of execution of the present invention, also can carry out combination in any, 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 (14)
1. direct-acting overflow valve, comprise there is filler opening (P) and valve body (101), the spool (102) of return opening (T) and the spring that this spool (102) is biased into normality sealing station, described spool (102) has oil-feed pressure-bearing surface (PA), the hydraulic oil of described filler opening (P) input can act on the upper resistance that overcomes spring to promote spool (102) of this oil-feed pressure-bearing surface (PA) and move and realize overflow, wherein
Described direct-acting overflow valve also comprises remote control mouth (V) and the hydraulic oil reaction chamber (X) being communicated with this remote control mouth (V), this hydraulic oil reaction chamber (X) is communicated with filler opening (P), hydraulic oil in described hydraulic oil reaction chamber (X) is identical with the force direction of described spring to the force direction of this spool (102), and the hydraulic oil effective active area of described oil-feed pressure-bearing surface (PA) is greater than the hydraulic oil effective active area of the compression face that is exposed to hydraulic oil reaction chamber (X) of described spool (102), so that the mobile active force of the driving spool (102) that the hydraulic oil of identical oil pressure forms described oil-feed pressure-bearing surface (PA) is greater than the mobile active force of prevention spool (102) that described compression face is formed.
2. direct-acting overflow valve according to claim 1, wherein, the outer circumferential face of described spool (102) is sliding combined with piston (103), and the inner peripheral surface of the valve pocket of the outer circumferential face of this piston (103) and described valve body (101) is slidably matched, one end end face of described piston (103) is exposed to described hydraulic oil reaction chamber (X), the first ladder stop surface (112) and protrusion that other end is formed on towards protrusion on the valve pocket inwall of described valve body (101) are formed on the second ladder stop surface (113) on described spool (102) outer circumferential face, contacting with the second ladder stop surface (113) with this first ladder stop surface (112), at described spool during in described normality sealing station, distance between described the first ladder stop surface (112) and the other end of described spool (102) is less than the distance between described the second ladder stop surface (113) and the other end of this spool (102).
3. direct-acting overflow valve according to claim 2, wherein, the spring chamber of described direct-acting overflow valve (Y) doubles as described hydraulic oil reaction chamber (X).
4. direct-acting overflow valve according to claim 3, wherein, described filler opening (P) and described spring chamber (Y) lay respectively at the opposite end of described spool (102), and the oil-feed pressure-bearing surface (PA) of described spool (102) is exposed in described filler opening (P).
5. direct-acting overflow valve according to claim 3, wherein, one end of described spool (102) extend in described spring chamber (Y), the end that extend into described spring chamber (Y) of this spool (102) is formed with spring seat location ladder surface and the first spring seat (108) is installed, and this first spring seat (108) is orientated the end face space that is exposed to described spring chamber (Y) of the end face towards described piston (103) and the described piston (103) that make this first spring seat (108) as by described spring seat location ladder surface.
6. direct-acting overflow valve according to claim 5, wherein, second spring seat (111) relative with described the first spring seat (108) is also installed in described spring chamber (Y), one end in contact of this second spring seat (111) and screw press (106), this screw press (106) screw thread is arranged on the plug (105) for sealing described spring chamber (Y).
7. direct-acting overflow valve according to claim 6, wherein, described spring comprises the first spring (109) and is positioned at inner and second spring (110) coaxial with this first spring (109) of this first spring (109), and the two ends of the two ends of this first spring (109) and the second spring (110) are set to respectively on described the first spring seat (108) and the second spring seat (111).
8. direct-acting overflow valve according to claim 6, wherein, described spring comprises the first spring (109) and the second spring (110), the two ends of described the first spring (109) are set to respectively on described the first spring seat (108) and the second spring seat (111), described the second spring (110) is supported between the end face and the supporting lip (115) on described spool (102) of described spring chamber dorsad (Y) of described piston (103), described the first spring seat (108) is threaded onto on described spool (102), to compress described the second spring (110) via described piston (103), make this second spring (110) form pretightening force.
9. direct-acting overflow valve according to claim 6, wherein, on described plug (105), be formed with the ring week stop lug (114) of stretching out in described spring chamber (Y), this encircles all stop lug (114) corresponding to the fringe region of described piston (103) end face, to encircle all stop lug (114) with this at this piston (103) when described spring chamber (Y) moves to precalculated position, contacts.
10. according to the direct-acting overflow valve described in any one in claim 1 to 9, wherein, described hydraulic oil reaction chamber (X) is communicated with described filler opening (P) by the damping hole being formed on described spool (102).
11. direct-acting overflow valves according to claim 10, wherein, valve pocket (104) is installed on described valve body (101), it is upper that described hydraulic control mouth (V) is formed on described valve pocket (104), and be communicated with described hydraulic oil reaction chamber (X) by the inside oil duct being formed on this valve pocket (104) and valve body (101).
12. direct-acting overflow valve valve groups, comprise direct-acting overflow valve, wherein, described direct-acting overflow valve is according to the direct-acting overflow valve described in any one in claim 1 to 11, and the remote control mouth (V) of this direct-acting overflow valve is connected in return opening (T) or the fuel tank of this direct-acting overflow valve via on-off control valve.
13. direct-acting overflow valve valve groups according to claim 12, wherein, described on-off control valve is bi-bit bi-pass solenoid directional control valve (2).
14. hydraulic overflow loops, wherein, this hydraulic overflow loop comprises that, according to the direct-acting overflow valve valve group described in claim 12 or 13, the filler opening of described direct-acting overflow valve (T) is communicated with working connection or the working oil path of hydraulic system, and return opening (T) is communicated with fuel tank.
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| CN201210175068.4A CN102678645B (en) | 2012-05-31 | 2012-05-31 | Direct-acting overflow valve, direct-acting overflow valve group and hydraulic overflow loop |
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