CN102606251B

CN102606251B - Variable valve actuator

Info

Publication number: CN102606251B
Application number: CN2012100951845A
Authority: CN
Inventors: 邓强泉; 娄征; 文韶
Original assignee: JIANGSU GONGDA POWER TECHNOLOGIES Co Ltd
Current assignee: Ningbo Hoyea Machinery Manufacture Co Ltd
Priority date: 2012-03-31
Filing date: 2012-03-31
Publication date: 2013-11-27
Anticipated expiration: 2032-03-31
Also published as: CN102606251A

Abstract

The invention discloses an actuator, whichis divided into a hydraulic control loop portion and a spring mechanical system portion and comprises a shell, an actuating cylinder, an actuating piston, a first fluid space, a second fluid space, a first piston rod, a second piston rod, a fluid bypass, a first spring system, a second spring system, a first flowing mechanism and a second flowing system. The shell is provided with an upper port and a lower port, the actuating cylinder is arranged in the shell, the actuating piston in the cylinder can move along a longitudinal axis, the first piston rod is connected to a first surface of the actuating piston, the second piston rod is connected to a second surface of the actuating piston, the first spring system is connected with the first piston rod and eccentrically presses the actuating piston along a second direction, and the second spring system eccentrically presses the actuating piston along a first direction. The invention further discloses two other actuators. The actuator has the advantages that the lift of a valve is variable, energy consumption is low, response speed is fast, valve crash speed is slow, control is simple and reliable, and the like.

Description

Variable valve actuator

Technical field

Present invention relates in general to actuator and correlation technique and system be used to controlling this actuator, and particularly, relate to the actuator of independent lift (or stroke or stroke) and timing control can be provided with minimal energy consumption.

Background technique

Can adopt various systems to come timing and the lift of effective control engine valve, improve performance, fuel economy, injection and other characteristics of motor.According to device or the actuator controlled, these systems can be divided into (electrohydraulic) machinery, electric liquid and dynamo-electric (being sometimes referred to as electromagnetism) form.According to the scope of controlling, can be divided into the form of lift range variable and timing, Variable Valve Time and lift range variable.They also can be divided into has cam (cam-based) or indirectly-acting and without cam or direct acting form.

In the situation that the system of cam is arranged, keep traditional engine cam system and revise a little, indirectly to control valve timing and/or valve lift.In without camming, traditional engine cam system is replaced fully with the electric liquid or the electromechanical actuator that directly drive each engine valve.Although provide wider controllability without camming, stop using (deactivation) of cylinder and valve for example, and have thus better fuel economy, the variable automobile valve system of all existing productions all has cam.

Dynamo-electric problem without camming comprises and soft landing (soft-landing), high electric power requires, scarce capacity is relevant difficulty, or restive lift and process the limited in one's ability of cylinder air pressure high and/or variation.Electricity liquid can overcome such problem usually without camming, but there is the problem of self really in it, and for example the performance under high engine speed and design or control are complicated, cause the conflict between response time and flow.In order under 6,000 to 7,000rpm, to move, at first actuator must accelerate then geared-down engine valve on the scope at 8mm within the time of 2.5 to 3 milliseconds.Engine valve must be traveling in the approximately peak velocity of 5 meter per seconds.These require to have reached the limit of traditional electrical liquid technology.

An approach that overcomes this performance limitations is, is similar to Mechatronic Systems the same, in electrohydraulic system, adds a pair of relative spring (opposing springs), and the moving-mass of itself and system comes together to produce spring-mass resonance or oscillation system.Under static state, this relative spring is arranged on engine valve between the endpoint location of this valve between two parties, namely opens and closes between position.In order to keep engine valve on an endpoint location, system must have certain locking framework, resists from this clean return force to spring, and it has accumulated potential energy on any one of two end points.When from an endpoint location to another end points position row, advancing, at first engine valve is driven by the spring return force and accelerates, and provides power by the potential energy of spring storage, until at the mid point of stroke, it reaches top speed and has corresponding kinetic energy herein; Then the return force of its antagonistic spring keeps travelling forward, and provides power by kinetic energy, until the other end, its speed drops to zero herein, and corresponding kinetic energy changes the potential energy of spring storage into.

With regard to the working principle that it is known, spring mass system this in the transformation of energy aspect very effectively and very reliable.A lot of technological development have been to design effectively and reliable locking-releasing mechanism, it can remain on engine valve its opening and closing position, discharge as requested, increase the engine cylinder air pressure that additional-energy comes friction compensation and alterable height, and land and hindered the unnecessary energy of breath before on the other end at it.As discussed above, exist the difficulty relevant to electromechanics or electromagnetic locking-releasing device.Also had the people at electric liquid, lock-carried out effort aspect the exploitation of releasing device.

The U.S. Patent No. 4 that is attributed to Daimler Chrysler (DaimlerChrysler), 930,464 what disclose is a kind of electric liquid actuator, it comprises two rod oil cylinders (double-ended rod cylinder), a pair of relative spring and bypass, described relative spring is tending towards piston is arranged at the centre of oil cylinder, described bypass is two cylinder chamber of short circuit on most of stroke, and like this, hydraulic jack is not wasted energy.When engine valve during in closed position, bypass is inoperative, piston is divided into larger unlatching side room and the less side room of closing by oil cylinder, and when opening side room and close side room while standing respectively high-voltage power supply and low pressure source, engine valve can lock, and this is owing on piston, producing the differential pressure opposite with return spring power.When engine valve was in enable possition, piston was divided into larger side room and the less unlatching side room closed by oil cylinder, and closed side room and high-voltage power supply is stood respectively in less unlatching side room and low pressure source can lock engine valve by larger.

No matter in enable possition or in closed position, by opening simply two-way triggering valve (2-way trigger valve), discharge the pressure in large chamber, eliminate thus the differential pressure on piston, trigger the swing power of spring mass system, carry out the release engine valve.This Twoway valves must cut out again very rapidly before stroke finishes, thereby large chamber pressure can be elevated to enough fast greatly with lock piston, and therefore engine valve is in its new endpoint location.This structure also has two-way and advances valve, on the top end at valve rod during opening stroke, to introduce extra driving force.

Aforementioned system has several potential problems.This two-way triggers valve and must be no more than in very short cycle of 3 milliseconds with in good time mode opening and closing.This two-way advances valve by the differential pressure driving in two cylinder chamber or the alleged stroke space of inventor, and has too many time lag and hydraulic pressure transient wave advancing between valve and cylinder chamber potentially.Near each stroke finished, larger cylinder chamber must carry out backfill by the fluid of being supplied with by a restrictor, and this requires restrictor member that sizable opening size is arranged.On the other hand, in the beginning of each stroke, this two-way triggers the pressure that valve must discharge larger chamber, and this large chamber is communicated with high-pressure fluid source by same restrictor.During closing stroke, until very near the end of stroke, do not have effective method to increase other hydraulic energy, if there is too large frictional loss, this will be a problem.Equally, this invention has no idea to regulate its lift.

U. S. Patent 5,595,148,5,765,515,5,809,950,6,167,853,6,491,007 and 6,601, also be attributed to Daimler Chrysler No. 552, these patents have disclosed U. S. Patent 4,930, the improvement of No. 464 instructions.Disclosed the U. S. Patent 5,595,148,5,765,515,5,809,950 and 6,167 of various hydraulic spring grease cup devices, 853 purport be open stroke start increase other hydraulic energy, overcome the air pressure of engine cylinder.A shortcoming of hydraulic spring grease cup is that its pressure descends rapidly in case engine valve movement starts.

At U. S. Patent 6,601, in No. 552, provide a kind of compress control method, on the variable part of valve lift, to keep constant pressure in the hydraulic spring grease cup device, yet this requires selector valve switching between the two positions within the very short cycle of 1 millisecond.In addition, this system comprises two Compress Springs: the first spring and the second spring are tending towards respectively engine valve component is driven into and closes and enable possition.Connect hydraulic spring grease cup device and the second Compress Spring entity.During the unlatching stroke is very most of, although there is the motion of valve, it is designed to attempt to keep pressure in hydraulic spring grease cup, and air pressure and other frictional force of therefore providing other driving force to overcome engine cylinder, cause the increase of the net flow body volume in the hydraulic spring grease cup device and the increase of the effective preload in the second Compress Spring, this is because due to the equilibrium of forces between hydraulic spring grease cup and Compress Spring.In valve-closing stroke subsequently, engine valve may not be pushed to fully and be closed always, and this is due to due to the higher resistance from the second Compress Spring.

The total problem of all patent family applications of invention is for each unlatching or closes two switching actions that stroke must have control valve.Another common problem is the length of the actuator of the Compress Spring that separated by hydraulic spring grease cup with two.When spring rows is listed on same axis, as U. S. Patent 5,809, disclose for No. 950, total height can be extraordinary.In other patent of this patent family application, spring is not arranged on linear axis, and what replace is in the bending of hydraulic spring grease cup place, but fluid inertia, frictional loss and transient state hydraulic pressure ripple and delay can become serious problems.Another common problem is only by swinging energy drives, close stroke, but the existence of actual frictional loss can cause serious threat for normal operation.For release or releasing mechanism, some embodiments adopt threeway to trigger the cell supercharging that valve makes oil cylinder momently, with two lip-deep pressure of equalizing piston, and the differential pressure on piston are reduced to zero from the pressure that is suitable for locking.Trigger valve and also must within the very short time cycle, realize two actions.

U. S. Patent 5,248, disclosed another kind of electric liquid actuator No. 123, it comprises two rod oil cylinders, is tending towards piston is arranged on to the middle a pair of relative spring of cylinder between two parties, and the bypass of two cylinder chamber of short circuit on most of stroke, like this, hydraulic jack is not wasted energy.Very similar with the patent of the Daimler Chrysler quoted, it has the larger hydraulic jack chamber that always is connected to high voltage supply.Yet different from Daimler Chrysler is that it adopts the five-way two-position valve to start the valve switching, and each stroke is only required a valve events.This valve has five external hydraulic line: low pressure source pipeline, high-voltage power supply pipeline, constant high-pressure export pipeline and two have export pipeline corresponding and switchable force value.The constant high-pressure export pipeline is connected with the larger chamber of oil cylinder.Two other export pipelines are connected to two ends of oil cylinder, and optionally with the less chamber of oil cylinder, are communicated with.With Daimler Chrysler discloses, be very similarly, its stroke start do not have effective ways to increase hydraulic energy, with compensation engine cylinder air pressure and frictional loss.It can not control the lift of valve.

No. ZL200680021728.6 (and corresponding U. S. Patent 7,302,920,7 of Chinese patent, 194,991 and 7,156, No. SV/AK/218/DELNP/2008, No. 058 and Indian patent application) disclosed another kind of electric liquid actuator, can provide the two-stage lift to control and stepless timing control.This technology also adopts dual spring pendulum and electric liquid locking-releasing device, similar techniques relatively before, and it has more effective locking-releasing device.

No. 200680028252.9 (and corresponding U. S. Patents 7 of Chinese patent application, 290,509,7,213,549 and 7,370, No. 615) disclosed another kind of electric liquid actuator, this technology also adopts dual spring pendulum and electric liquid locking-releasing device, and except intrinsic stepless timing control ability, it can also carry out stepless lift control.

Summary of the invention

The technical problem that the present invention mainly solves is to provide a kind of variable valve actuator, possesses variable valve lift, low energy consumption, and high response speed, valve crash speed is little, controls the characteristics such as simple and reliable.

For solving the problems of the technologies described above, the technological scheme that the present invention adopts is: a kind of actuator is provided, comprises:

Housing, have upper end-hole and lower end mouth;

Actuation-cylinder in described housing, first direction longitudinally or second direction have respectively first end and the second end;

Power piston in described oil cylinder, have first surface and second surface, moves along the longitudinal;

The first fluid space, limited by the first end of described actuation-cylinder and the first surface of described power piston;

The second fluid space, limited by the second end of described actuation-cylinder and the second surface of described power piston;

The first piston bar, be connected to the first surface of described power piston;

The second piston rod, be connected to the second surface of described power piston;

Fluid bypass, when described power piston did not have any of abundant first end near described actuation-cylinder and the second end, described fluid bypass is short circuit described first fluid space and described second fluid space effectively;

The first spring system, be connected with described first piston bar, along the described power piston of second direction bias voltage; And have at least two original states, the initial bias voltage power of at least two different sizes is provided to described power piston;

The second spring system, along the described power piston of first direction bias voltage;

First-class actuation mechanism, coordinate with described first piston bar, controls fluid between described first fluid space and described upper end-hole and be communicated with;

The second actuation mechanism, coordinate with described the second piston rod, controls fluid between described second fluid space and described lower end mouth and be communicated with;

Wherein: when described fluid bypass was opened basically, at least one in described first-class actuation mechanism and described second actuation mechanism closed;

When described fluid bypass was closed basically, each in described first-class actuation mechanism and described second actuation mechanism was opened at least in part.

In a preferred embodiment of the present invention, described the first spring system, comprise the first driving spring, spring seat, spring control cylinder block and plunger, described the first driving spring places oneself in the midst of described spring seat and described spring is controlled between cylinder block, described spring seat is connected with described first piston bar, described spring is controlled in cylinder block an oil pocket, and described plunger has a runner; Described housing comprises a cavity and its enable port; Described the first spring system is arranged in described cavity, in described plunger, runner is communicated with described oil pocket and described its enable port, described spring is controlled cylinder block and is vertically moved in described cavity with respect to described housing, to change along the longitudinal the decrement of described the first driving spring.

Another technological scheme that the present invention adopts is: a kind of actuator is provided, comprises:

Housing, have upper end-hole and lower end mouth, and described upper end-hole also comprises the first upper end-hole and the second upper end-hole;

The first spring system, along the described power piston of second direction bias voltage;

When described fluid bypass was closed basically, each in described first-class actuation mechanism and described second actuation mechanism was opened at least in part;

Described first piston bar comprises first piston bar the first neck, first piston bar first shaft shoulder, first piston bar the second neck and first piston bar second shaft shoulder with the order near described power piston, its each have outside dimensions;

Described first-class actuation mechanism comprises the first control hole with Inner Dimension;

The Inner Dimension of described the first control hole is a bit larger tham the outside dimensions of described first piston bar first shaft shoulder and described first piston bar second shaft shoulder, and be greater than significantly the outside dimensions of described first piston bar the first neck and described first piston bar the second neck, and when described fluid bypass is opened substantially, described first piston bar first shaft shoulder and described the first control hole are vertically overlapping, and described first fluid space and described upper end-hole are cut off;

The terminal stage approached to the first end of described actuation-cylinder when the first surface of described power piston, described first piston bar first shaft shoulder is the part of overlapping described the first control hole between described the first upper end-hole and described the second upper end-hole vertically, to cut off the first upper end-hole and the second upper end-hole.

In a preferred embodiment of the present invention, the outside dimensions of described first piston bar the second shoulder axle is less than the outside dimensions of described first piston bar the first shoulder axle, accordingly, described the first control hole comprises first portion and the second portion matched with described first piston bar the first shoulder axle and described first piston bar the second shoulder axle respectively, the Inner Dimension of described first portion and described first piston bar the first shoulder axle relative sliding ground are complementary, and the outside dimensions relative sliding ground of the Inner Dimension of described second portion and described first piston bar the second shoulder axle is complementary.

In a preferred embodiment of the present invention, described first piston bar first shaft shoulder has at least one first segment chute near on the end face of described first piston bar the second neck.

In a preferred embodiment of the present invention, when described actuator also comprises the first buffer with the first end of advancing at described power piston near described actuation-cylinder, the speed that suppresses described power piston, described actuator also comprises the first hydraulic power that is communicated in described upper end-hole, and described the first buffer is positioned on the runner that is communicated with described the second upper end-hole and described the first hydraulic power.

In a preferred embodiment of the present invention, described the first buffer comprises the first one-way valve, first segment head piece and the first relief valve in parallel.

In a preferred embodiment of the present invention, described the first relief valve is adjustable relief valve.

Housing, have upper end-hole and lower end mouth, and described lower end mouth also comprises the first lower end mouth and the second lower end mouth;

Described the second piston rod comprises second piston rod the first neck, second piston rod first shaft shoulder, second piston rod the second neck and second piston rod second shaft shoulder with the order near described power piston, its each have outside dimensions;

Described second actuation mechanism comprises the second control hole with Inner Dimension;

The Inner Dimension of described the second control hole is a bit larger tham the outside dimensions of described second piston rod first shaft shoulder and described second piston rod second shaft shoulder, and be greater than significantly the outside dimensions of described second piston rod the first neck and described second piston rod the second neck, and when described fluid bypass is opened substantially, described second piston rod first shaft shoulder and described the first control hole are vertically overlapping, and described second fluid space and described lower end mouth are cut off;

The terminal stage approached to the second end of described actuation-cylinder when the second surface of described power piston, described second piston rod first shaft shoulder is the part of overlapping described the second control hole between the first lower end mouth and the second lower end mouth vertically, to cut off described the first lower end mouth and described the second lower end mouth.

In a preferred embodiment of the present invention, described second piston rod first shaft shoulder has at least one second section chute near on the end face of second piston rod the second neck.

In a preferred embodiment of the present invention, when described actuator also comprises the second buffer with the second end of advancing at described power piston near described actuation-cylinder, the speed that suppresses described power piston, described actuator also comprises the second hydraulic power that is communicated in described lower end mouth, and described the second buffer is positioned on the runner that is communicated with described the second lower end mouth and described the second hydraulic power.

In a preferred embodiment of the present invention, described the second buffer comprises the second one-way valve, second section head piece and the second relief valve in parallel.

The invention has the beneficial effects as follows: variable valve actuator of the present invention, possess variable valve lift, low energy consumption, high response speed, valve crash speed is little, controls the characteristics such as simple and reliable.Especially, (1) has comprised the first unique driving spring control structure, and compact structure, lead reliable and stable, shortened the first piston pole length and reduced whole actuator movements part quality, improved actuator movements speed, reduced energy consumption; (2) comprised and effectively having discharged and Cushioning Design, solved the contradiction on 26S Proteasome Structure and Function between release and buffering.

The accompanying drawing explanation

Fig. 1 is the structural representation of little lift original state one preferred embodiment of variable valve actuator valve of the present invention;

Fig. 2 is the structural representation that the little lift valve operating of variable valve actuator valve shown in Figure 1 is opened to maximum rating;

Fig. 3 is the structural representation of variable valve actuator valve high-lift original state shown in Figure 1;

Fig. 4 is the structural representation that variable valve actuator valve high-lift valve shown in Figure 1 is opened to maximum rating;

Fig. 5 is the another kind of embodiment's of variable valve actuator of the present invention structural representation;

In accompanying drawing, the mark of each parts is as follows:

The 110-longitudinal axis, the 200-housing, 211-the first upper end-hole, 212-the second upper end-hole, 221-the first lower end mouth, 222-the second lower end mouth, the 230-actuation-cylinder, the 231-first end, the 232-the second end, the 240-fluid bypass, 241-the first edge, 242-the second edge, the 250-cavity, 251-the first confined planes, 252-the second confined planes, the 260-its enable port, 271-the first control hole, 272-the second control hole, the 300-power piston, the 310-first surface, the 320-second surface, 410-first piston bar, 411-first piston bar the first neck, 412-first piston bar the first shoulder axle, 413-first piston bar the second neck, 414-first piston bar the second shoulder axle, 4121-first segment chute, 420-the second piston rod, 421-second piston rod the first neck, 422-second piston rod the first shoulder axle, 423-second piston rod the second neck, 424-second piston rod the second shoulder axle, 4221-second section chute, the 511-spring seat, 512-the first driving spring, the 513-spring is controlled cylinder block, 5131-cylinder body upper surface, 5132-cylinder body lower surface, the 5133-oil pocket, the 514-plunger, the 5141-runner, the 515-semi-ring, the 521-cotter seat, 522-the second driving spring, the 523-cylinder body, 524-valve guide, 611-the first hydraulic power, 612, the 612 '-the first one-way valve, 613, 6121-first segment head piece, 614-the first relief valve, 621-the second hydraulic power, 622-the second one-way valve, 623, 6241-second section head piece, 624, the 624 '-the second relief valve, the 700-valve, the 710-engine valve head, 720, engine valve seat, the 730-valve stem, 800-primer fluid potential source.

Embodiment

Below in conjunction with accompanying drawing, preferred embodiment of the present invention is described in detail, thereby so that advantages and features of the invention can be easier to be it will be appreciated by those skilled in the art that, protection scope of the present invention is made to more explicit defining.

Refer to Fig. 1 and Fig. 3, the embodiment of the present invention comprises:

A kind of actuator, comprise: housing 200, in this housing, axis 110 and along second direction (in the accompanying drawings from top to the direction of bottom), have its enable port 260, cavity 250, the first control hole 271, the first upper end-hole 211, the second upper end-hole 212, actuation-cylinder 230, fluid bypass 240, the second lower end mouth 222, the first lower end mouth 221, the second control hole 272 along the longitudinal; And be arranged on 250 li of cavitys the first spring system (mark), be arranged on first piston bar 410 in the first control hole 271, be arranged on power piston 300 in actuation-cylinder 230 and fluid bypass 240, be arranged on the second piston rod 420 in the second control hole 272; And second spring system (mark), engine valve 700; And the second hydraulic power 621 be connected with lower end mouth with the first hydraulic power 611 that primer fluid potential source 800 that its enable port 260 is communicated with is connected with upper end-hole.In Fig. 1, the first hydraulic power 611 and the second hydraulic power 621 controllably are connected with oil supply system by hydraulic control valve (such as rapid reversal valve, not showing in Fig. 1), switching between system high (PH) low (PL) is pressed.Under the working condition of Fig. 1, the first hydraulic power 611 and the second hydraulic power 621 are respectively under system low-voltage (PL) and system high pressure (PH).System low-voltage (PL) can be, a low pressure of more stable that control by a back pressure system, may be also the low pressure of directly leading to fuel tank.Primer fluid potential source 800 is under spring pilot pressure (PS), spring pilot pressure (PS) can pass through certain hydraulic control valve (showing in Fig. 1) and controllably be connected with oil supply system, and spring pilot pressure (PS) also can switching between system high pressure (PH) or low (PL) pressure.In Fig. 1, spring pilot pressure (PS) is got a low value, is not enough to that spring is controlled to cylinder block 513 and drives along second direction.

The first upper end-hole 211 and the second upper end-hole 212 can be commonly referred to as upper end-hole, and upper end-hole will comprise in the first upper end-hole 211 and the second upper end-hole 212 at least; The first lower end mouth 221 and the second lower end mouth 222 can be commonly referred to as lower end mouth, and lower end mouth will comprise in the first lower end mouth 221 and the second lower end mouth 222 at least.

Described first piston bar 410 with the order near described power piston 300 namely along on the first direction direction of bottom to top (in the accompanying drawings from), comprising successively first piston bar the first neck 411, first piston bar first shaft shoulder 412, first piston bar the second neck 413 and first piston bar second shaft shoulder 414; With the first control hole 271, form first-class actuation mechanism.The Inner Dimension of described the first control hole 271 is a bit larger tham the outside dimensions of described first piston bar first shaft shoulder 412 and described first piston bar second shaft shoulder 414, and is greater than significantly the outside dimensions of described first piston bar the first neck 411 and described first piston bar the second neck 413.

Embodiment shown in Fig. 1, first piston bar first shaft shoulder 412 is identical with the outside dimensions of second shaft shoulder 414, and corresponding the first control hole 271 can only have an outside dimensions, further preferred situation: the outside dimensions of described first piston bar the second shoulder axle 414 is less than the outside dimensions of described first piston bar the first shoulder axle 412, accordingly, described the first control hole 271 comprises first portion and the second portion matched with described first piston bar the first shoulder axle 412 and described first piston bar the second shoulder axle 414 respectively, the Inner Dimension of described first portion and described first piston bar the first shoulder axle 412 relative sliding ground are complementary, the outside dimensions relative sliding ground of the Inner Dimension of described second portion and described first piston bar the second shoulder axle 414 is complementary.

Described the second piston rod 420 with the order near described power piston 300 namely along on the second direction direction of top to bottom (in the accompanying drawings from), comprising successively second piston rod the first neck 421, second piston rod first shaft shoulder 422, second piston rod the second neck 423 and second piston rod second shaft shoulder 424; With the second control hole 271, form the second actuation mechanism.The Inner Dimension of described the second control hole 271 is a bit larger tham the outside dimensions of described second piston rod first shaft shoulder 422 and described second piston rod second shaft shoulder 424, and is greater than significantly the outside dimensions of described second piston rod the first neck 421 and described second piston rod the second neck 423.

Similar with first-class actuation mechanism: the outside dimensions of second piston rod first shaft shoulder 422 and second shaft shoulder 424 is identical, can be also that the outside dimensions of described first piston bar the second shoulder axle 424 is less than the outside dimensions that described first piston bar first is takeed on axle 422.

In actuation-cylinder 230, have the first fluid space limited by actuation-cylinder first end 231 and power piston first surface 310 and limit the second fluid space by actuation-cylinder the second end 232 and power piston second surface 320.

Between first end 231 and the second end 232, be, between actuation-cylinder 230, the first edges 241 and the second edge 242, fluid bypass 240 is arranged, fluid bypass 240 provides the hydraulic pressure short circuit on large minister's degree of actuation-cylinder 230.By this hydraulic pressure short circuit, fluid can flow with basically very low resistance between first fluid space and second fluid space, and whole actuation-cylinder 230 is in the pressure basically equated.When power piston 300 first surfaces 310 surpass bypass the first edge 241 in a first direction, or power piston 300 second surfaces 320 are while surpassing bypass the second edge 242 on second direction, and the hydraulic pressure short circuit is all inoperative.Longitudinal space between bypass the first edge 241 and actuation-cylinder first end 231 is first effective oil pressure chamber, and its length is the L1 in Fig. 1.Longitudinal space between bypass the second edge 242 and actuation-cylinder the second end 232 is second effective oil pressure chamber, when power piston 300 not with first effective oil pressure chamber and second effective oil pressure chamber in during one of any joint, fluid bypass 240 is effective.

Described the first spring system comprises the first driving spring 512, spring seat 511, spring is controlled cylinder block 513 and plunger 514, described the first driving spring 512 places oneself in the midst of described spring seat 511 and spring is controlled between cylinder block 513, described spring seat 511 is connected with described first piston bar 410, between can be fixing by semi-ring 515, described spring is controlled in cylinder block 513 oil pocket 5133, described plunger 514 is fixedly attached on described housing 200 and extends in described oil pocket 5133, plunger 514 can be also same one with housing 200 in mechanism, in described plunger 514, there is a runner 5141 to be communicated with described oil pocket 5133 and its enable port 260.In this real example, design the first driving spring 512 overheads and concentric with first piston bar 410, have runner 5141 in plunger 514, and the to-and-fro motion while controlling cylinder block 513 compression the first driving spring 512 for spring realizes guiding, joins oil.Have the following advantages: avoid the first driving spring 512 and first piston bar 410 not only concentric but also when axial overlap is arranged, because of the first piston bar 410 that spring control gear (spring seat 511) and the effective working stroke of spring cause long; Shortened the length of first piston bar 410, corresponding the reducing of first piston bar 410 diameters energy, quality is light, has effectively reduced whole actuator movements part quality, has improved actuator movements speed, has reduced energy consumption.The first driving spring 512 control structure compactnesses, lead reliable and stable, avoids the first driving spring 512 when compression, to produce lateral force.Adopt two ends and the housing supporting structure of piston rod; While making piston rod movement, obtain maximum effective bearing length, reduced to greatest extent the side direction moment on the piston rod, improved the stability of actuator movements.

If the enclosed cavity of cavity 250 not necessarily resembling in Fig. 1, in fact produce the image of feeling suffocated in order to prevent when spring is controlled cylinder block 513 motion, should add a passage (meaning in Fig. 1) that guarantees cavity 250 and ambient air circulation.The top of housing 200 is continuous with housing 200 other parts or direct (expression in Fig. 1) continuously even structurally, and top and the other parts of main housing 200 do not have relative movement.

Described the second spring system comprises cotter seat 521, the second driving spring 522, valve guide 524 and cylinder body 523, cotter seat 521 is connected with valve stem 730 1 ends, valve stem 730 the other ends are connected with engine valve head 710, described cylinder body 523 is between cotter seat 521 and engine valve head 710, on valve guide 524 suit cylinder bodies, valve stem 730 is from passing valve guide cover, and described the second driving spring 522 is sleeved on valve stem 730 and with cylinder body 523, contacts with cotter seat 521 simultaneously.

Described the first upper end-hole 211 directly is communicated with the first hydraulic power 611 by runner, the second upper end-hole 212 is communicated with the first hydraulic power 611 by the first buffer again, and described the first buffer comprises the first one-way valve 612 arranged side by side, first segment head piece 613 and the first relief valve 614; Described the first lower end mouth 221 directly is communicated with the second hydraulic power 621 by runner, the second lower end mouth 222 is communicated with the second hydraulic power 621 by the second buffer again, and described the second buffer comprises the second one-way valve 622 arranged side by side, second section head piece 623 and the second relief valve 624.The wherein effect of one-way valve: forward, for pressure oil, oppositely ends oil return and forms buffer cavity; Restriction effect: buffering throttling; The restriction of reasonable orifice size is set, makes piston rod seating velocity when the last braking of buffer stage little, stable, cushioning effect is subjected to influence of temperature change little.The relief valve effect: by overflow, limit the buffering surge pressure, avoid in buffering course reducing valve motion speed too early and extend buffer time, when high engine speeds turned round, long buffer time can affect normal distribution function; Relief valve can preferentially adopt the adjustable relief valve of oil pressure relief, and the buffering surge pressure can regulate and control according to the difference of loading condition.Valve buffer time can be less than 0.7 millisecond when high engine speeds, so relief valve should have very high speed of response in design.

Described first piston bar first shaft shoulder 412 has at least one first segment chute 4121 near on the end face of first piston bar the second neck 413, and described first segment chute 4121 is the variable throttling area, diminishes gradually along the second direction area; Described second piston rod first shaft shoulder 422 has at least one second section chute 4221 near on the end face of second piston rod the second neck 423, and described second section chute 4221 is the variable throttling area, diminishes gradually along the first direction area.The design of throttling groove variable throttling area, make piston rod obtain buffering course stably.

Figure 1 shows that the little lift original state of actuator valve, described the first driving spring 512 has just possessed certain amount of spring compression when original state, spring is controlled cylinder block upper surface 5131 and is contacted with cavity the first confined planes 251, i.e. the second hydraulic power voltage supply of power piston 300 cavity of resorption voltage supply, along first direction, act on the reaction force of hydraulic action much larger than the first driving spring 512 along second direction on power piston 300 second surfaces 320, the first surface 310 of power piston 300 contacts with first end 231, now first piston bar 410 and the second piston rod 420 are in original state, valve-closing.

In conjunction with Fig. 1, shown in Figure 2, the little lift working procedure of actuator valve is as follows: when hydraulic control circuit switches to respectively system high pressure (PH) and system low-voltage (PL) by the first hydraulic power 611 and the second hydraulic power 621, the epicoele of power piston 300 and cavity of resorption also are subject to respectively system high pressure (PH) and system low-voltage (PL), power piston 300 and piston rod 410 and 420 spring make a concerted effort and the acting in conjunction of hydraulic coupling under stretch out fast certain stroke and (approximate the length L 1 in first effective oil pressure chamber of actuation-cylinder 230, accurate stroke is affected by amount of spring compression and system pressure within the specific limits), driving valve 700 opens, the first driving spring 512 decrements discharge, the second driving spring 522 decrements increase, second piston rod first shaft shoulder 422 is closed the cavity of resorption oil circuit simultaneously, valve stays open state.When hydraulic control circuit switches back the first hydraulic power 611 and the second hydraulic power 621 respectively while being system low-voltage (PL) and system high pressure (PH), the epicoele of power piston 300 and cavity of resorption also are subject to respectively system low-voltage (PL) and system high pressure (PH), and power piston 300 and piston rod 410 and 420 are retracted as the original state of Fig. 1 with joint efforts and under the acting in conjunction of hydraulic coupling at spring.The motion of whole actuator is mainly to provide power (conversion of gesture kinetic energy) by disymmetry Compress Spring (first, second driving spring 512 and 522) telescopic oscillating, oil hydraulic circuit supplements the energy loss in spring reciprocating vibration process, and controls the valve switch state.

The present invention makes piston rod different from the system fuel feeding logic of stroke end of a period during the stage in the back and forth movement starting stage to the design of piston rod, during along starting stage that the first and second directions are moved, system oil return is directly got back to fuel tank by the first upper end-hole 211 and the first lower end mouth 221 respectively at piston rod; And when the stroke moved along the first and second directions is ended the stage, system oil return must arrive respectively the damping device of setting after the second upper end-hole 212 and the second lower end mouth 222 buffer cavitys, finally just can get back to fuel tank, with the damping device cooperating, realize two ends stroke end of a period buffering like this.

Be illustrated in figure 3 actuator valve high-lift original state, spring pilot pressure (PS) is got a high value, the hydraulic coupling foot drives along second direction in spring being controlled to cylinder block 513, until controlling cylinder block lower surface 5132, spring contacts with cavity the second confined planes 252, greatly increased the pre compressed magnitude (than the state in Fig. 1) of the first driving spring 512, the equinoctial point of making a concerted effort of the first driving spring 512 and the second driving spring 522 is moved along second direction, to increase the lift of valve.The epicoele of the first hydraulic power 611 and the second hydraulic power 621(so power piston 300 and cavity of resorption are also) difference connected system low pressure (PL) and high pressure (PH), along first direction, act on reaction that hydraulic action on power piston 300 second surfaces 320 is greater than first,

second driving spring

512 and 522 make a concerted effort (now along second direction), the first surface 310 of power piston 300 contacts with first end 231, now piston and piston rod 300,410 and 420 are in original state, valve-closing.

In conjunction with Fig. 3, shown in Figure 4, actuator valve high-lift working procedure is as follows: when hydraulic control circuit switches to respectively system high pressure (PH) and system low-voltage (PL) by first and second hydraulic power 611 and 621 (shown in Figure 4), the epicoele of power piston 300 and cavity of resorption also are subject to respectively system high pressure (PH) and system low-voltage (PL), and power piston 300 and piston rod 410 and 420 stretch out along second direction with joint efforts and under the acting in conjunction of hydraulic coupling fast at spring; In this process, the hydraulic oil of the epicoele of power piston 300 supplements by one-way valve 612.After the first surface 310 of power piston goes out the first edge 241, fluid bypass 240 is short circuit first fluid space and second fluid space effectively, the epicoele of power piston 300 and cavity of resorption are substantially under same pressure and lose corresponding hydraulic coupling and save unnecessary hydraulic pressure energy consumption, and power piston 300 and piston rod 410 and 420 continue to move along second direction under the effect that inertial force and spring are made a concerted effort.After power piston 300 and piston rod 410 and 420 row are crossed the halfway of about lift, the spring direction of making a concerted effort to start to change, resisted motion, and at the volley kinetic energy is changed into and puts aside potential energy, but power piston 300 and piston rod 410 and 420 also move downward under the ordering about of inertial force, and progressively slow down.After the second surface 320 of power piston 300 is crossed the second edge 242, fluid bypass 240 is closed, the epicoele of power piston 300 and cavity of resorption be recovery system high pressure (PH) and system low-voltage (PL) effect respectively also, second piston rod first shaft shoulder 422 separates the first lower end mouth 221 and the second lower end mouth 222, using the second lower end mouth 222 as buffer cavity (the second section chute 4221 on second piston rod first shaft shoulder 422 is as the part of buffer structure), power piston 300 and piston rod 410 and 420 are after buffer deceleration, the second surface 320 of power piston 300 overlaps with the second end 232 of housing 200, movement travel ends, drive valve 700 opening to high-lift, the first driving spring 512 decrements discharge, the second driving spring 522 decrements increase, hydraulic coupling foot on power piston 300 keeps the open mode of valve 700 oppositely making a concerted effort of opposing driving spring.In above-mentioned buffering course, one-way valve 622 is in closed condition always under the effect of backpressure; Second section chute 4221 release portion hydraulic oil when buffering initial is back to the actuation-cylinder epicoele and causes bounce-back to prevent excessively buffering; Second section head piece 623 is in circulation status always, attempts to be created in the compensator or trimmer pressure in buffer cavity by its choked flow character, and this compensator or trimmer pressure acts on the cushion effect that forms power piston second surface 320 and reduces power piston and the speed of the movement parts that is connected; Due to the variation of engine operating condition, above-mentioned buffering element also has narrow limitation together, may cause the compensator or trimmer pressure transient state too high and draw backlash or buffer time long, the second relief valve 624 can be opened fast to transient state and reduces the buffering surge pressure for this reason.

When hydraulic control circuit switches back the first hydraulic power 611 and the second hydraulic power 621 respectively while being system low-voltage (PL) and system high pressure (PH), the epicoele of power piston 300 and cavity of resorption also are subject to respectively system low-voltage (PL) and system high pressure (PH), power piston 300 and

piston rod

410 and 420 are retracted as the original state of Fig. 3 along first direction with joint efforts and under the acting in conjunction of hydraulic coupling at spring, and the logical course of its movement process is similar and opposite with the valve opening procedure.

The little lift operating mode of valve is mainly used in engine start and low speed small load condition, and valve high-lift operating mode is mainly used in the middle and high fast high load working condition of motor.

In Fig. 4, when the second piston rod 420 moved to along the end of a period of second direction stroke during the stage, second piston rod first shaft shoulder 422 separates respectively the first lower end mouth 221 and the second lower end mouth 222, using the first lower end mouth 221 as buffer cavity; Second section chute 4221 on second piston rod first shaft shoulder 422 is as the part of buffer structure.

Figure 5 shows that the variation example of actuator structure embodiment illustrated in fig. 1, with a large difference of actuator structure shown in Figure 1, be: the first upper end-hole 211 and the first lower end mouth 221 be direct oil sump tank 615 all, this structure in some design proposal is simpler, and does not affect the original intention (i.e. the oil return function of the first upper end-hole 211 and the first lower end mouth 221) of this two-port design function; Damping device is comprised of one-way valve in parallel and relief valve.

The large difference of another of Fig. 5 and actuator structure shown in Figure 1 is: restriction also designs one or more oil grooves or the openning on the valve port of relief valve or one-way valve in Fig. 5, and oil groove also can be through-flow on a small quantity at relief valve or closed check valve.In Fig. 5, first segment head piece 6121 is combined on the valve port of the first one-way valve 612 ', and second section head piece 6241 is combined on the valve port of the second relief valve 624 '.

Embodiment in relative Fig. 1, another kind of embodiment of the present invention can make the diameter of first piston bar the second shoulder axle 414 be less than the diameter of first piston bar the first shoulder axle 412, in order to move while being descending an extra driving force arranged along second direction at valve 700, to help to overcome extra resistance to motion (similar engine exhaust port is run into while opening); Accordingly, the first control hole 271 also can be divided into the two-part (not showing in Fig. 1) that match with first piston bar the first shoulder axle 412 and the second shoulder axle 414 respectively, and their internal diameter is complementary with the external diameter relative sliding ground of first piston bar the first shoulder axle 412 and the second shoulder axle 414 respectively.

In a lot of diagrams with in describing, flowing medium is assumed to oil or hydraulic pressure or liquid form, and in most cases, same concept can suitably be applied to air pressure or water quality oil hydraulic actuator and system after design in proportion.Equally, at this term adopted " fluid ", mean and comprise liquids and gases.

Although in foregoing description and Fig. 1-5, first and second piston rod almost symmetry, first and second mobile mechanism under them or corresponding is almost symmetry also, but the present invention also comprises actuator, piston rod that one of them is instructed for foregoing description and Fig. 1-5 and under or corresponding mobile mechanism, and another piston rod and under or corresponding mobile mechanism can adopt the piston rod in prior art and the mechanism design (with reference to Chinese patent ZL200680021728.6) that flows.

The foregoing is only embodiments of the invention; not thereby limit the scope of the claims of the present invention; every equivalent structure or equivalent flow process conversion that utilizes specification of the present invention and accompanying drawing content to do; or directly or indirectly be used in other relevant technical fields, all in like manner be included in scope of patent protection of the present invention.

Claims

1. actuator comprises:

Housing, have upper end-hole, lower end mouth, cavity and its enable port;

Actuation-cylinder in described housing, first direction longitudinally and second direction have respectively first end and the second end;

The first spring system, be connected with described first piston bar, along the described power piston of second direction bias voltage; And have at least two original states, the initial bias voltage power of at least two different sizes is provided to described power piston; Described the first spring system, comprise the first driving spring, spring seat, spring control cylinder block and plunger, described the first driving spring places oneself in the midst of described spring seat and described spring is controlled between cylinder block, described spring seat is connected with described first piston bar, described spring is controlled in cylinder block an oil pocket, and described plunger has a runner; Described the first spring system is arranged in described cavity, in described plunger, runner is communicated with described oil pocket and described its enable port, described spring is controlled cylinder block and is vertically moved in described cavity with respect to described housing, to change along the longitudinal the decrement of described the first driving spring;

2. actuator comprises: housing, have upper end-hole and lower end mouth, and described upper end-hole also comprises the first upper end-hole and the second upper end-hole;

3. actuator according to claim 2, is characterized in that, described housing also comprises a cavity and its enable port;

Described the first spring system, comprise the first driving spring, spring seat, spring control cylinder block and plunger, described the first driving spring places oneself in the midst of described spring seat and described spring is controlled between cylinder block, described spring seat is connected with described first piston bar, described spring is controlled in cylinder block an oil pocket, and described plunger has a runner; Described the first spring system is arranged in described cavity, in described plunger, runner is communicated with described oil pocket and described its enable port, described spring is controlled cylinder block and is vertically moved in described cavity with respect to described housing, to change along the longitudinal the decrement of described the first driving spring.

4. actuator according to claim 2, it is characterized in that, the outside dimensions of described first piston bar the second shoulder axle is less than the outside dimensions of described first piston bar the first shoulder axle, accordingly, described the first control hole comprises first portion and the second portion matched with described first piston bar the first shoulder axle and described first piston bar the second shoulder axle respectively, the Inner Dimension of described first portion and described first piston bar the first shoulder axle relative sliding ground are complementary, the outside dimensions relative sliding ground of the Inner Dimension of described second portion and described first piston bar the second shoulder axle is complementary.

5. actuator according to claim 2, is characterized in that, described first piston bar first shaft shoulder has at least one first segment chute near on the end face of described first piston bar the second neck.

6. actuator according to claim 2, it is characterized in that, when described actuator also comprises the first buffer with the first end of advancing at described power piston near described actuation-cylinder, the speed that suppresses described power piston, described actuator also comprises the first hydraulic power that is communicated in described upper end-hole, and described the first buffer is positioned on the runner that is communicated with described the second upper end-hole and described the first hydraulic power.

7. actuator according to claim 6, is characterized in that, described the first buffer comprises the first one-way valve, first segment head piece and the first relief valve in parallel.

8. actuator according to claim 7, is characterized in that, described the first relief valve is adjustable relief valve.

9. actuator comprises:

First-class actuation mechanism, coordinate with described first piston bar, controls fluid between described first fluid space and described upper end-hole and be communicated with; Described first-class actuation mechanism comprises the first control hole with Inner Dimension;

10. actuator according to claim 9, is characterized in that, described second piston rod first shaft shoulder has at least one second section chute near on the end face of second piston rod the second neck.

11. actuator according to claim 9, it is characterized in that, when described actuator also comprises the second buffer with the second end of advancing at described power piston near described actuation-cylinder, the speed that suppresses described power piston, described actuator also comprises the second hydraulic power that is communicated in described lower end mouth, and described the second buffer is positioned on the runner that is communicated with described the second lower end mouth and described the second hydraulic power.

12. actuator according to claim 11, is characterized in that, described the second buffer comprises the second one-way valve, second section head piece and the second relief valve in parallel.

13. actuator according to claim 9, is characterized in that, described housing also comprises a cavity and its enable port;