DE102006021723A1 - Lift adjustment device for double eccentric drives - Google Patents

Abstract

Stroke adjusting systems are used in many areas of hydraulics as well as vehicle and mechanical engineering. In the case of such double eccentric drives, there are no modern adjustment devices suitable for inexpensive manufacture. The task is to create improved adjustment devices with the inclusion of new constructive means and mechatronic components. The solution is achieved through the combined use of hydraulic forces and spring forces (10), with new supply and distribution systems (13; 14; 15) of a hydraulic control mechanism and the resulting control pressures being used. With the use of mechatronic actuators, very short adjustment times are achieved. The invention is best characterized by FIG.

Description

The The invention relates to a device for continuous adjustment of the working stroke in driven by radial eccentric or axial eccentric Pumps of all kinds, in particular in common rail pumps for diesel and gasoline injection systems.

But also in drive and control systems in internal combustion engines, vehicles, Processing machines u. a. Aggregates can be the device application Find. Hubverstellende facilities are in manifold versions known. In addition to lever systems, between a cam and the To be driven piston are turned on, especially double eccentric used for stroke adjustment.

at such designs known with radial cams is on an inner, mounted with the drive shaft associated eccentric second outer eccentric and from the angular position of both eccentrics to one another results certain stroke size.

The known designs differ in the design of the adjustment of the eccentric. Mainly a hydraulic swing leaf system is proposed, as in the documents CH 2 26 285 and US 3,180,178 the case is.

In this case, the loading and unloading of the corresponding hydraulic chambers is controlled by piston valves and handwheels. In which US Pat. No. 2,592,237 the angular position of the eccentric is set via a handwheel and gears.

Also the publication DD 31201 works with hydraulic piston valve and handwheel analogous to the above-mentioned publications.

The DE 32 22 577 uses the reaction forces occurring between the eccentrics for "arbitrary adjustment" and uses it for freewheels, piston valves and other components.

The the latter document, but also the above-mentioned writings make elaborate Constructions with a large number of individual parts. For one large-scale Use these known types are not very suitable.

Of the Invention is based on the object with stroke-adjusting radial and axial cam drives with in- or mounted on one another eccentrics simple, self-acting To arrange control and regulating devices and thus cost cam drives to create with continuous stroke adjustment.

• – das Verstellsystem mit einer Kombination aus hydraulischen Kräften und Federkräften arbeitet,
• – die hydraulische Steuerung verbessert und vereinfacht ist,
• – die angetriebenen umlaufenden Teile (Antriebswelle) drehschieberartig den Zustrom eines Steuermediums in das Verstellsystem steuern und
• – in weiterer Ausgestaltung des Systems mechanisch/mechatronische Stellglieder in das Verstellsystem eingeschaltet sind.

This object is achieved in that

• - the adjustment system works with a combination of hydraulic forces and spring forces,
• The hydraulic control is improved and simplified,
• - The driven rotating parts (drive shaft) like a rotary valve control the flow of a control medium in the adjustment and
• - In a further embodiment of the system mechanical / mechatronic actuators are turned on in the adjustment.

The The invention is illustrated below in several embodiments.

The Drawings show:

1 a longitudinal section through the device with radial cam and hydraulic adjustment system,

2 a section along the line II in 1 at 0-stroke position,

3 a section analog 2 at 180 ° stroke position,

4 a section analog 2 at 45 ° stroke position,

5 a section along the line II-II in 1 (one-sided feed),

6 a section analog 5 (two-sided infeed),

7 a section from the 1 ( 6 concerning),

8th a section analog 6 with modified control pressure feed,

9 a section from the 1 ( 8th concerning),

10 the principle of a mechanical / mechatronic adjustment system,

11 an application of the invention

12 in axial piston machines

In the 1 is one in the case 1 mounted drive shaft 2 with an inner eccentric 3 and a tax evasion 4 whose center ME by the amount e from the center M of the drive shaft 2 is offset.

On the inner eccentric 3 is an exex centers 5 stored, whose firmly connected to him housing part 6 an inner contour 7 has.

This inner contour 7 forms together with the control eccentric 4 an annular space concentric with ME 8th that includes the adjustment system.

A lid 9 closes the annulus 8th from which, at the same time, the axial guidance of the outer eccentric 5 is made. A torsion spring 10 is on the one hand with the drive shaft 2 on the other hand with the housing part 6 /Cover 9 firmly connected and constitutes a main element of the 5 described control and regulating system.

In operative connection with the eccentrics 3 and 5 is a roller tappet 11 in the case 1 is guided and drives the actual work system (piston, lever member o. Ä.). Depending on the type of radial piston pumps while several pistons concentric with the drive shaft 2 be arranged.

Furthermore, it can be between the eccentrics 3 and 5 several lubricant channels 12 located, the z. B. are acted upon in a hydraulic pump with the pressure prevailing in the housing interior pressure.

The 1 at the same time shows a feed for a tax medium into the tax and regulation system. This is a Zuführbohrung 13 about one in the drive shaft 2 located annular channel 14 continuous with distribution wells 15 ( 5 ) connected.

It can also be with the drive shaft 2 connected rotating piece with improved hydraulic seal the connection from the housing 1 to the drive shaft 2 produce. According to the invention, however, the supply can also be controlled such that waiving the annular groove 14 a rotary slide-like feeder between 13 and 15 he follows. Here is the radial, with 13 corresponding distributor bore 15 the eccentrics 3 ; 5 assigned so that only in the u. T. position (bottom dead center, zero crossing) the connection between 13 and 15 is made. This reduces the adjustment forces. Outside the range of u. T. position, the system is hydraulically locked. At the same time, vibration phenomena imposed on the system by the drive or by flow and pressure fluctuations are suppressed.

The 2 shows the assigned position of the eccentric 3 and 5 such that a 0 stroke is set. The center ME is analogous 1 by the amount e above the center M of the drive shaft 2 ,

The 3 shows opposite 2 the 180 ° adjustment of the outer eccentric 5 , The center ME is shifted by 2e with respect to M, it is set with the 180 ° stroke the maximum stroke. This stroke is usually not used in the technical design, but apply a partial twist.

In the 4 For example, a partial rotation of 45 ° is shown, the eccentric center ME migrates on a circular path with the radius e.

The 5 shows the adjustment in the initially known training with swing wings.

With the control eccentric 4 (and thus the inner eccentric 3 and the drive shaft 2 - 1 ) are firmly connected to the swing wings 16 , with the housing part 6 (and thus the outer eccentric 5 - 1 ) the swing wings 16a ,

In the position shown should now 6 . 16a clockwise so opposite 4 ; 16 preceded that the maximum required stroke is set.

According to the invention, this position is achieved in that the torsion spring 10 ( 1 ) and the auxiliary springs 17 this twist until it stops at the stop pin 18 cause. The aggregate, z. As a pump moves in this way with maximum stroke and thus the largest flow (main stream).

In order to achieve smaller flow rates down to the O-promotion, is about the elements 13 ; 14 ; 15 ( 1 ) By a fast-switching control valve, a control current with a certain control pressure on the drive shaft 2 into the pressure chambers 19 fed. Consequently, the housing part 6 including outer eccentric 5 turned back counterclockwise, so hub and flow reduced. According to the invention a control loop is thus integrated in the simplest way in the device. At z. B. constant input speed of the pump and constant control valve position, a pressure level is maintained in a consumer. If the consumer takes a smaller main flow, the control flow is increased, the control pressure in the pressure chamber 19 rises. This will make the parts 5 ; 6 against the action of the springs 10 ; 17 moved towards garbage promotion. With increased main current in the consumer, the opposite conditions occur.

That is in the spring chambers 20 accumulating leakage medium can through the auxiliary bores 21 in the case 1 flow away. If, as is often the case, the case 1 inside is below a certain lower form, this form is also in the spring chambers 20 and supports the action of the springs 10 ; 17 , With the size The pump pressure can thus be exercised in a certain way influence on the control behavior.

The 6 shows in addition to 5 the adjustment system designed such that in support of the springs 10 ; 17 a hydraulic control pressure in the rear spring chambers 20 is fed. These are additional distribution wells 15a ( 6 ) in the drive shaft 2 and the control eccentric 4 arranged. The auxiliary bores 21 omitted.

In what way the reciprocal admission of the chambers 19 ; 20 According to the invention, is in 7 shown.

It shows as a section of 1 the control system integrated directly into the body of the device.

A piston valve 22 , which is right next to the drive shaft 2 is arranged, controls the inflow and outflow of the control medium into the chambers 19 and 20 ( 6 ) over the distribution wells 15 and 15a , This piston valve 22 can be operated in different ways.

In the 7 becomes the piston valve 22 for example, via an angle lever 23 and a mechatronic actuator 24 (Magnet, piezoelectric actuator) in the left end position, by a compression spring 25 moved to the right end position.

Likewise, the piston valve 22 through one into the chamber 26 introduced hydraulic pressure to be moved, but also the introduction of hydraulic pressure on both sides of the spool 22 , optionally connected with single or double-acting compression springs 25 and corresponding attacks are possible embodiments.

In the middle position of the piston valve shown 22 the system is hydraulically locked. When shifted to the left, the middle ring groove comes 27 With 15 to cover, the chambers 19 ( 6 ) are applied while the chambers 20 above 15a and the right outer annular groove 27a be relieved - the hub of the device is reduced. The outflowing medium flows through the drainage channels 28 the interior of the case 1 to.

With a shift of 22 to the right, the inverse conditions occur through the intervention of 27 . 27b one.

In all these embodiments of the control and regulating system, the rotary slide-like supply of the control pressure according to the invention, as at 1 is described. Instead of the spool valve 22 Of course, another double-acting valve can be used.

In the 8th is an embodiment with four chambers 19 ; 20 represented, wherein in each chamber two channels open, here Zulaufbohrung 29 and drain hole 30 called.

For the end positions of the rotation of the housing part 6 opposite the control eccentric 4 here are two stop bolts 18 arranged, which make sure the holes 29 ; 30 not be shut off.

The 9 shows the embodiment according to 8th the adjustment system integrated in the device. The here also possible control by a piston valve 22 For example, it should be replaced by two separately controllable mechatronic actuators (magnet, piezoactuator) 24 ; 24a ,

The control pressure is via the supply bore 13 and those in the drive shaft 2 located distribution well 15 all four chambers 19 ; 20 ( 8th ) supplied without circuit of a piston valve or other valve constantly, but also controlled by a rotary slide. It can be a throttle 31 a certain throttle effect in the influx to the chambers 19 ; 20 cause.

The System is thus hydraulically locked. Because in all chambers of the same pressure prevails, leakage currents between the chambers do not occur.

For an angle adjustment between the swing wings 16 ; 16a ( 8th ) opens the actuator 24 or 24a the associated hydraulic valve, which mutually the chambers 19 or 20 ( 8th ) and uses the stroke adjustment of the system.

In order to gives this embodiment safe-acting and structurally simple means of solving the inventive task at.

The 10 shows a mechanical / mechatronic adjustment system. The drive shaft 2 and thus the inner eccentric 3 ( 1 ) sit down to a threaded spindle 33 while the outer eccentric 5 ( 1 ) a the housing part 6 corresponding threaded spindle 33a has. Both threaded spindles 33 ; 33a face each other coaxially and carry multi-start threads with large pitch, the between 33 ; 33a is opposite (right or left). A sliding sleeve 34 each with corresponding internal threads engages in both threaded spindles 33 ; 33a and sets the positive connection between the parts 2 ; 6 and thus the eccentrics 3 ; 5 ago. An axial movement of the sliding sleeve 34 , the through a mechatronic interlocking such. As a proportional solenoid, a hydraulic control pressure or purely mechanically levers o. Ä. Can be made limbs, leads to a relative rotation between the eccentrics 3 ; 5 and thus for the stroke adjustment of the system.

A compression spring 25 can be used to return the sliding sleeve 34 serve.

Due to the opposing thread pitches on 33 ; 33a lift the resulting from the torque transmission longitudinal forces in the sliding sleeve 34 on, so that the adjustment forces are reduced.

The 11 and 12 show the application of the device according to the invention in axial piston machines.

The 11 shows one with the drive shaft 2 tightly connected axial eccentric 35 and about the adjustment and control system is the second axial eccentric 35a with the axial eccentric 35 connected. In the illustration after 11 are both eccentrics 35 ; 35a so posed against each other, that for in the case 1 guided displacer 36 a 0-stroke is set.

The 12 shows opposite 11 the 180 ° adjustment of both eccentrics 35 ; 35a to each other, it is set the maximum stroke. In the practical embodiment, you will also apply a partial adjustment, including all means of the invention 8th ; 15 ; 15a ; 16 ; 16a ; 19 ; 20 can be used as they too 1 to 9 have been described.

In consideration drawn pamphlets

• DE 3222577 C2
• DE 3505133 C2
• DD 31201
• CH 226285
• US 3,180,178
• US 2,592,237
• EP 1293667 A1
• DE 3803735 A1
• DE 3720567 A1
• DE 3542938 C2
• DE 3513736 C2

1

casing

2

drive shaft

3

internal eccentric

4

control cam

5

outer eccentric

6

housing part

7

inside office

8th

annulus

9

cover

10

torsional

11

roller plunger

12

lubricant channel

13

feed bore

14

annular channel

15; 15a

distributor bores

16; 16a

rotary vane

17

auxiliary spring

18

stop pin

19

pressure chamber

20

spring chamber

21

auxiliary bore

22

spool

23

bell crank

24; 24a

actuator

25

compression spring

26

chamber

27; 27a; 27b

ring grooves

28

spillway

29

inlet bore

30

drain hole

31

throttle

32; 32a

hydraulic valve

33; 33a

screw

34

sliding sleeve

35; 35a

axial cam

36

displacer

Claims (9)

Hubverstelleinrichtung for Doppelexzenterantriebe with continuously adjustable double eccentrics and hydraulically / mechanically controlled swing leaf system, characterized in that a spring system ( 10 ; 17 ) and / or a hydraulic control pressure swing wing ( 16 ; 16a ) up to a stop bolt ( 18 ) in the sense of a Hubvergrößerung, in the opposite direction Hubverkleinerung, adjusted, such that one in the housing ( 1 ) in the immediate vicinity of the adjustment system ( 2 ; 4 ; 8th ; 10 ; 16 ; 16a ; 17 ; 19 ; 20 ) built-in switchable valve combination ( 22 ; 24 ; 24a ; 32 ; 32a ) or one with threaded spindles ( 33 ; 33a ) operating system the movement of the swing wings ( 16 ; 16a ) controls. Hubverstelleinrichtung according to claim 1, characterized in that a Zuführbohrung ( 13 ) in the housing ( 1 ) with an annular groove ( 14 ) in the rotating drive shaft ( 2 ) or in a rotating piece connected to it continuously and a hydraulic control medium via distributor bores ( 15 ) in the adjustment system ( 2 ; 4 ; 8th ; 10 ; 16 ; 16a ; 17 ; 19 ; 20 ) is initiated. Hubverstelleinrichtung according to claim 1, characterized in that the feed bore ( 13 ) with the distribution wells ( 15 ) discontinuously in Connection stands and the hydraulic control medium rotator like the adjustment ( 2 ; 4 ; 8th ; 10 ; 16 ; 16a ; 17 ; 19 ; 20 ) supplies, so that only for the range of u. T. position of the roller tappet ( 11 ) the connection between supply bore ( 13 ) and distribution well ( 15 ) is made. Hubverstelleinrichtung according to claim 1, 2 or 3, characterized in that a in the housing ( 1 ) applied hydraulic pre-pressure via auxiliary bores ( 21 ) the force of the springs ( 10 ; 17 ) supported. Hubverstelleinrichtung according to claim 1, 2 or 3, characterized in that a separate in the spring chambers ( 20 ) fed hydraulic control medium the force of the springs ( 10 ; 17 ), such that a hydraulic or mechatronic / mechanical elements ( 23 ; 24 ) moving piston valve ( 22 ) or another double-acting valve the hydraulic control medium the pressure / spring chambers ( 19 ; 20 ) alternately feeds. Hubverstelleinrichtung according to claim 1, 2 or 3, characterized in that in each pressure chamber ( 19 ) and in each spring chamber ( 20 ) via an inlet bore ( 29 ) and via a drain hole ( 30 ) a control medium is zuführbar and deductible, such that in all chambers ( 19 ; 20 ) through the inlet via ( 15 ; 29 ) an equally large control pressure is present and over ( 15a ; 30 ) by means of actuators ( 24 ; 24a ) and hydraulic valves ( 32 ; 32a ) a separately controllable discharge of the chambers ( 19 ; 20 ) he follows. Hubverstelleinrichtung according to claim 1, characterized in that the interconnected and mutually adjustable parts ( 2 ; 3 ; 5 ; 6 ) with threaded spindles ( 33 ; 33a ), which have opposing pitches, are equipped and a hydraulically or mechanically actuated sliding sleeve ( 34 ) with the threaded spindles 33 ; 33a ) is in operative connection. Hubverstelleinrichtung according to claim 1 to 7, characterized in that lubricant channels ( 12 ) between the inner eccentric ( 3 ) and the outer eccentric ( 5 ) are arranged and with the interior of the housing ( 1 ) keep in touch. Hubverstelleinrichtung according to claim 1 to 6, characterized in that in axial piston machines with the drive shaft ( 2 ) fixedly connected axial eccentric ( 35 ) via the adjustment and control system with a second axial eccentric ( 35a ) and all means ( 8th ; 15 ; 15a ; 16 ; 16a ; 19 ; 20 ) between the axial eccentrics ( 35 ; 35a ) are turned on.