EP2920436A1

EP2920436A1 - Oscillating motor adjuster with an electromagnetically actuated hydraulic valve

Info

Publication number: EP2920436A1
Application number: EP13826718.2A
Authority: EP
Inventors: Marc Hohmann; Matthias Lang; Michael OPPEL
Original assignee: Hilite Germany GmbH
Current assignee: Hilite Germany GmbH
Priority date: 2012-11-16
Filing date: 2013-11-14
Publication date: 2015-09-23
Anticipated expiration: 2033-11-14
Also published as: DE112013005475B4; WO2014075675A1; US9631525B2; CN104704207B; US20150330267A1; DE112013005475A5; CN104704207A; EP2920436B1; DE102012111033A1

Abstract

The invention relates to an oscillating motor camshaft adjuster (14) with an electromagnetically actuated hydraulic valve (12) that has a hollow piston (19) inserted into a bore (85) and longitudinally displaceable by means of an electromagnet (100), which hollow piston (19) is intended for distributing hydraulic fluid to two pressure chambers (9, 10) of the working connections (A, B) assigned to the oscillating motor camshaft adjuster (14). The first working connection (A) branches off from the bore (85) directly adjacent to the electromagnet (100). The hollow piston (19) has a circumferential stay with a control edge (107) facing the electromagnet (100). Thus a space (103) inside the bore (85) is bordered by the stay (102) and the electromagnet (100). A run-off opening (104) is provided in the hollow channel (19) between the stay (102) and the electromagnet (100). This run-off opening (104) hydraulically connects the space (103) to a run-off channel (105) leading to a tank drain (T) inside the hollow piston (19). The stay (102) can be displaced in a direction extending the first working connection (A) in the flow cross-section (106) by means of a force (F-M) of the electromagnet (100) supplied with current. This force (F-M) is directed counter to an elastic force (F-F) that presses the stay (102) in the direction reducing the flow cross-section (106). A throttle point (108) is provided at the stay (102), which throttle point (108) is arranged between the flow cross-section (106) and the space (103). Thus a high control quality is achieved.

Description

Schwenkmotornockenwellenversteller with an electromagnetically actuated

hydraulic valve

The invention relates according to the one-part claim 1 a

Schwenkmotornockenwellenversteller with an electromagnetically actuated hydraulic valve.

From DE 10 2009 022 869 A1 discloses a Schwenkmotornockenwellenversteller with an electromagnetically operated hydraulic valve is already known. This

Schwenkmotornockenwellenversteller has a longitudinally displaceable by means of an electromagnet used in a bore hollow piston for distributing hydraulic fluid to two pressure chambers. These pressure chambers are

Assigned to work connections. From the bore of the first working connection goes from the electromagnet immediately adjacent. A hollow piston has a circumferential web with a solenoid facing the control edge. Thus, a space within the bore is limited on the one hand by the web and on the other hand by the electromagnet. From this room is a drain opening, which connects the room with a leading to a tank drain drainage channel hydraulically. The web is displaceable by means of a force of the energized electromagnet in a direction widening the first working port in the flow cross-section.

This force is directed against a spring force, which the bridge in the

Flow cross-section depressing direction. The bridge is interrupted by a circumferential annular groove. This annular groove corresponds with an outgoing from a bore inner wall of the bore inner rib, the

only with de-energized electromagnets of the hollow piston in the unactuated position

- From this second working port hydraulic fluid through the annular groove

- As well as from the first working port hydraulic fluid

flows to the tank drain. This ensures that a spring-loaded

Locking pin in the swivel camshaft adjuster of both

Pressure chambers is pressure-free and thus in a locked center locking position can engage. A special feature of this center locking position compared to some common Endlagenverriegelungen is that for locking from both pressure chambers no pressure may come.

Moreover, from the documents DE 10 2006 012 733 B4 and DE 10 2006 012 775 B4 Schwenkmotornockenwellenversteller already known with a hydraulic valve. In these documents and camshaft alternating torques are shown.

To also with internal combustion engines with very strongly fluctuating

Camshaft alternating torques to keep the control quality high, the DE 10 2010 014 500 A1 provides that a switching position of the hydraulic valve is proportionally controllable, in which the pressure peaks of the work port to be relieved with respect to the supply connection and the work connection to be loaded are locked.

From EP 1 476 642 B1 is already a hydraulic valve for a

Schwenkmotornockenwellenversteller known which has two hollow piston, which are supported by a coil spring to each other. Thus, a gap between the two hollow piston is obvious and closable.

The object of the invention is to provide a Schwenkmotornockenwellenversteller with a high quality control.

This object is achieved with the features of claim 1.

According to the invention, when the current is withdrawn from the electromagnet of the hydraulic valve, it is already begun relatively early to discharge the hydraulic fluid from the pressure chamber to the tank outlet. Moreover, the characteristic curve, which represents the volume flow of this discharge over the current, is relatively linear. In this case, the Schwenkmotornockenwellenversteller two working ports A, B on. The first working port A is immediately adjacent to the electromagnet. An axially displaceable within a bore hollow piston has a

circumferential web with a solenoid facing the control edge. This forms a space within the bore, which is bounded on the one hand by the web on the hollow piston and on the other hand by the electromagnet. The hydraulic fluid can from this space via a drain opening in the hollow piston to a

Tank drain T are led out. In a non-inventive

Hydraulic valve could, however, the Schwenkmotornockenwellenversteller - for example due to camshaft alternating torques - strive to push more hydraulic fluid into the room, as can be pushed out of the room through the recess. Then at a rapid reduction in the current at the electromagnet, the hollow piston could not initially against the first

Work port A are moved under a relatively high pressure room. That the hollow piston could not follow the electromagnet and a gap would open there. Due to the lack of displacement of the hollow piston, the flow cross section at the working ports could not change. For this reason, according to the invention a throttle point between the first

Work connection A and the room provided. As a result of the hydraulic fluid which is thus supplied only to a small extent by the working connection A, the space can be relieved more quickly via the recess and the discharge to the tank outlet T takes place earlier. The characteristic curve, which represents the flow of this discharge above the flow, is thus more linear than without a restriction. This allows a precise regulation.

The smaller the number of cylinders per camshaft - i. per cylinder bank - is. Thus, the invention can play their particular advantage in three-cylinder engines and six-cylinder engines in V-arrangement. But even with other engines, the invention

Find application. In a particularly advantageous embodiment, a pump check valve is provided. Pressure peaks, which come as a result of camshaft alternating torques, are supported on this pump check valve. In this case, the check valve may be designed as a band-shaped check valve, which is inserted into an annular space or an annular groove of the hydraulic valve. However, it is also possible, for example, to carry out the check valve as a ball check valve in a funnel-shaped valve seat, as such a ball check valve is already known from DE 10 2007 012 967 B4.

In an advantageous embodiment of the invention, the hydraulic valve as

Central valve executed. Such a central valve has space advantages. In addition to central valves, there are still the decentralized or external hydraulic valves for operating the Schwenkmotornockenwellenverstellers. When external

Hydraulic valve run the hydraulic channels for adjusting the camshaft from Schwenkmotornockenwellenversteller to a separate timing drive cover with the screwed there hydraulic valve or to the cylinder head with the screwed in there hydraulic valve. With the hydraulic lines from

Pivot camshaft phaser go to external hydraulic valve

Line losses accompanied. In addition, the controls are from the external

Hydraulic valve not implemented as dynamically as the central valve. The likewise hydraulic central valve is radially inside the rotor hub of the

Schwenkmotornockenwellenverstellers arranged.

In a further advantageous embodiment of the invention is the second

Working port B provided a second throttle point. The second throttle is generally less effective than the first throttle. In the second throttle point of the hollow piston is namely pressure balanced when the

Connection order AB-T1 -P is. Without this second throttle point, however, the hollow piston would be torn when opening from the second working port B to the tank outlet T1 relatively abruptly in the direction of the electromagnet. The second throttle point causes but here a delay, so that the hydraulic valve is better to regulate.

Further advantages of the invention will become apparent from the other claims, the description and the drawings.

The invention is explained in more detail with reference to an embodiment. Show

1 is a Schwenkmotornockenwellenversteller in a sectional view,

Fig. 2 in a half section, a hydraulic valve for adjusting the

Schwenkmotornockenwellenverstellers according to FIG. 1, wherein the hydraulic valve has a throttle point,

Fig. 3 in a half section, a hydraulic valve without the invention

Throttle point,

4 is a graph comparing a characteristic of the hydraulic valve of FIG. 2 with the characteristic of the hydraulic valve of FIG. 3, FIG.

5 in an alternative embodiment, the hydraulic valve as a central screw,

Fig. 6 in a sectional view taken along line Vl-Vl of Fig. 5 and Fig. 7, the hollow piston and

Fig. 7 shows a detail of the hollow piston in a plan view.

With a Schwenkmotornockenwellenversteller 14 shown in FIG. 1, the angular position on the camshaft 18 relative to a drive wheel 2 is changed continuously during operation of an internal combustion engine. By twisting the Camshaft 18, the opening and closing times of the gas exchange valves are shifted so that the engine brings its optimal performance at the respective speed. The Schwenkmotornockenwellenversteller 14 has a cylindrical stator 1 which is rotatably connected to the drive wheel 2. In the exemplary embodiment, the drive wheel 2 is a sprocket over which a chain, not shown, is guided. The drive wheel 2 may also be a toothed belt wheel, via which a drive belt is guided as a drive element. About this drive element and the drive wheel 2, the stator 1 is drivingly connected to the crankshaft.

The stator 1 comprises a cylindrical stator base body 3, on the inside of which protrude webs 4 at equal intervals radially inwardly. Intermediate spaces 5 are formed between adjacent webs 4, into which, via a hydraulic valve 12 shown in more detail in FIG. 2, pressure medium is introduced. The hydraulic valve 12 is designed as a central valve. Between adjacent webs 4 protrude wings 6, which project radially outward from a cylindrical rotor hub 7 of a rotor 8. These wings 6 divide the spaces 5 between the webs 4 in each case in two pressure chambers 9 and 10th

The webs 4 lie with their end faces sealingly against the outer circumferential surface of the rotor hub 7. The wings 6 in turn lie with their end faces sealingly against the cylindrical inner wall of the stator main body 3.

The rotor 8 is rotatably connected to the camshaft 18. In order to change the angular position between the camshaft 18 and the drive wheel 2, the rotor 8 is rotated relative to the stator 1. For this purpose, depending on the desired direction of rotation, the pressure medium in the pressure chambers 9 or 10 is pressurized, while the respective other pressure chambers 10 or 9 are relieved to the tank. In order to pivot the rotor 8 counterclockwise relative to the stator 1 into the illustrated position, an annular first rotor channel in the rotor hub 7 is pressurized by the hydraulic valve 12. From this first rotor channel then lead further channels 1 1 in the pressure chambers 10. This first rotor channel is assigned to the first working port A. To the rotor 8, however, in the

To pivot clockwise, a second annular rotor channel in the rotor hub 7 is pressurized by the hydraulic valve 12. This second rotor channel is assigned to the second working port B. These two rotor channels are arranged with respect to a central axis 22 axially spaced from each other.

The Schwenkmotornockenwellenversteller 14 is placed on the designed as a hollow tube 16 built camshaft 18th For this purpose, the rotor 8 is placed on the camshaft 18. The Schwenkmotornockenwellenversteller 14 is pivotable by means of the apparent in Fig. 2 hydraulic valve 12.

Within the hollow tube 16, a sleeve 15 associated with the hydraulic valve 12 is inserted coaxially. In the central bore 85 of this bushing 15, a hollow piston 19 is slidably guided against the force of a helical compression spring 24. For this purpose, the helical compression spring 24 is supported on the one hand on the hollow piston 19 and on the other hand fixed to the housing. To the plant for the helical compression spring 24 is within the

Hollow piston 19 a ring 88 pressed with a Federfußführung. On the part of the hollow piston 19, the helical compression spring 24 is guided in a radial spring guide 193.

This radial spring guide 193 is on the outside as a second web 1 12 of two webs 102, 1 12 executed. With this second bridge 1 12, the second

Work port B are changed in the flow cross-section 125.

On the hollow piston 19 is a plunger 20 of an electromagnet 100 at.

Shown in FIG. 2 is the position in which the hollow piston 19 is located at maximum energized electromagnet 100. In this case, the second working port B is supplied with hydraulic pressure by a supply port P lying between the two working ports A, B. The hydraulic fluid flows through a Control groove 1 1 1, which forms axially between the two webs 102, 1 12. in the

In return, the hydraulic fluid from the first working port A

associated pressure chambers 9 via

a flow cross-section 106 on a transverse bore 101,

a throttle point 108,

a space 103 within the bush 15,

a drain opening 104 in the hollow piston 19,

- A drain passage 105 in the hollow piston 19th

led to a tank drain T.

The two working ports A, B and the intervening

Supply port P are designed as axially spaced transverse bores 101, 109, 1 10 in the bush 15. Only one transverse bore 101 or 109 or 1 10 per connection A, P, B is shown in the drawing. However, several transverse bores are arranged circumferentially offset per connection A, P, and B. The supply port P leads via a check valve 1 13 in the middle

Cross hole 109 to the control groove 1 1 1.

The hollow piston 19 is in the bore 85 by means of the electromagnet 100th

longitudinally. From this bore 85 thus goes from the first working port A. This working port A is the electromagnet 100 immediately adjacent and starting from the bore 85. The this first working port A associated transverse bore 101 is associated with a first on the hollow piston 19 circulated web 102. This web 102 has a control edge 107 facing the electromagnet 100. Thus, the space 103 is limited within the bore 85 on the one hand by the web 102 and on the other hand by the electromagnet 100. Between this web 102 and the electromagnet 100, the drain opening 104 in

Hollow piston 19 is provided. This drain opening 104 hydraulically connects the space 103 with the outflow channel 105 leading to the tank drain T within the hollow piston 19. The web 102 at the first working port A is by means of a force FM of the energized electromagnet 100 in a first working port A in Flow cross-section 106 expanding direction displaced. This flow cross-section 106 is formed between the control edge 107 and an inner edge 192 of the transverse bore 101. The force FM is opposite to a spring force FF, the web 102 in the flow cross-section 106th

sliding down decreasing direction. At the web 102, a throttle point 108 is provided, which is arranged between the flow cross-section 106 and the space 103.

Once the hollow piston 19 is pushed out of the - not graphically represented - unactuated by the plunger 20 end position so far that the

Flow section 106 opens, a volume flow Q-A-T remains over the

Throttle 108 open. From the opening of the flow cross-section 106, the volume flow Q-A-T remains open via the throttle point 108 regardless of how far away in the direction of the electromagnet 100 the hollow piston 19 is moved.

This is because a hydraulic path 199 leading from the throttle 108 to the space 103 remains open regardless of how far in the direction of

Electromagnet 100 hinfort the hollow piston 19 is moved.

The throttle point 108 is opposite the first working port A.

- With decreasing force F-M of the electromagnet 100 due to the spring force F-F to the end position of the hollow piston 19 of

- The electromagnet 100 facing the control edge 107 of the web 102 and

- The first working port A associated inner edge 192nd

closable.

However, the throttle body 108 is permanently open in any position of the hollow piston 19 to the space 103.

If, on the other hand, the hollow piston 19 does not engage in the drawing as a result of the FM force being released from the plunger 20 of the electromagnet 100 from the helical compression spring 24 shifted shown end position, so the hydraulic fluid from the

Supply port P directed to the first working port A. In this case, the hydraulic fluid flows from the supply port P or its transverse bore 109 via the control groove 1 1 1 in the transverse bore 101 of the first working port A. Im

In return, the hydraulic fluid from the second port B associated pressure chambers 10 by the bridge from 1 to 12 Tankabfluss T released

Transverse bore 1 10 removed.

Moreover, the hollow piston 19 can still be adjusted in a middle blocking position in the two working ports A, B in greater measure with pressure

be acted upon as the hydraulic fluid can be removed. Thus, the Schwenkmotornockenwellenversteller 14 is fixed in this angular position.

A housing part 121 of the electromagnet 100 is fixedly connected to a component, in which the bore 85 is incorporated. This component is realized here by means of the bushing 15.

The electromagnet 100 has the plunger 20. The plunger 20 is located on the

Hollow piston 19 and is through an opening 123 in a pole core 122 of the

Electromagnet 100 guided therethrough. This opening 123 allows an exchange of hydraulic fluid between the solenoid 100 and the space 103. When the plunger 20 is extended, hydraulic fluid flows into the solenoid 100. However, when the plunger 20 retracts, hydraulic fluid flows out of the solenoid 100 into the space 103 ,

By means of sufficient energization of the electromagnet 100, the plunger 20 is moved against the spring force F-F. When de-energized electromagnet 100, the plunger 20 is in the end position.

The throttle point 108 is shown as a very thin annular gap 1 14. This annular gap 1 14 joins the web 102 at. This throttle point 108 causes, in the case of high at the first working port A pending pressure of the pressure to the space 103 drops sharply. Upon withdrawal of the force FM of the electromagnet 100, the hydraulic fluid can be discharged from the space 103 through the drain opening 104 to the tank drain without the discharged amount of hydraulic fluid immediately from

Working port A is refilled. The hollow piston 19 can follow the ram 20 early with the name of the force F-M. With the early displacement of the web 102, the flow cross-section 106 also decreases at an early stage.

The characteristic curve 120 of the hydraulic valve 12 is shown in FIG. 4. This characteristic is shown in a diagram which represents the volume flow Q-A-T from the first working port A to the tank outlet T via the current applied to the electromagnet 100. The maximum current Imax in FIG. 4 represents the right end of the characteristic 120.

With the dashed characteristic curve 140, by contrast, the behavior of a

Hydraulic valve 212 shown, which can be seen in Fig. 3. In this

Hydraulic valve 212, no throttle point 108 is provided. Falls at

Solenoid 200 of the hydraulic valve 212, the current from Imax to 12 from, so the magnetic force F-M decreases. However, the hollow piston 219 does not move, since the poppet 219 can not displace the hydraulic fluid from the space 203, since hydraulic fluid from the first working port A nachdrückt. Thus, the force due to the pressure conditions in the space 203 plus the magnetic force F-M of the

Solenoid 100 even greater than the spring force F-F of the helical compression spring 224. At the current 13, the magnetic force has fallen so far that the

Hollow piston 19 begins to move. With this movement, the flow cross-section 106 at the first working port A also decreases.

Fig. 5 shows in an alternative embodiment, the hydraulic valve as

Central screw 405. The screw shaft forms the sleeve 215 for guiding the hollow piston 219. It shows the end position, in which a

Hollow piston 219 with de-energized electromagnet 300 is located. The hollow piston 219 is in the end position on a disc 390, which does not seal a space 303 against a second tank outlet T2. Instead, one is

Flow of hydraulic fluid possible. It is from an axially adjacent to the two working ports A, B and a first tank drain T1

Supply port P of the first working port A via the hollow piston 219 supplied with hydraulic pressure. The hydraulic fluid passes through a filter 410 and the check valve 313, which is band-shaped. The check valve 313 is inserted into an inner ring groove of the bore 385 of the central screw 405. The bore 385 thus runs in the central screw 405, which has a screw head 404. In the area of this screw head 404, the drain opening 304 is provided. In this case, the drainage channel 305 is formed between the screw head 404 and the electromagnet 300. This drainage opening 304 leads to the second tank drainage T2, which forms a common tank drainage T with the first tank drainage T1.

The throttle point 308 is designed as a circumferentially limited material recess 270 of the web 302. In this case, a plurality of such circumferentially limited material recesses 270 are provided on the circumference of the web 302. The

uniform distribution of the arrangement of these multiple material recesses 270 can be taken in an analogous manner of FIG. 6. However, FIG. 6 shows a second throttle point 271, which is located in FIG. 5 in the region of the line VI-VI.

The first working connection A has an inner annular groove 401, whose one inner edge 253 together with a control edge 272 of the respective material recess 270 forms the flow cross section.

The throttle point 308 is opposite the first working port A.

- With decreasing force F-M of the electromagnet 300 due to the spring force F-F to the end position of the hollow piston 219 of

- The electromagnet 300 facing the control edge 272 of the web 302 and - The first working port A associated inner edge 253 closed.

However, in each position of the hollow piston 219, the throttle point 308 is permanently open to the space 303.

Over the entire axial travel of the hollow piston 219, a hydraulic path 399 leading from the throttle point 308 to the space 303 remains open regardless of how far the hollow piston 219 is moved in the direction of the electromagnet 300.

In Fig. 7 is particularly clear that the material recesses 270 are rounded. This achieves a uniform opening of the flow cross-section instead of a sudden opening.

The first working port A is disposed between the second working port B and the electromagnet 300. The hollow piston 219 has a second circumferential rib 302 facing away from the electromagnet 300

Control edge 400 on. This control edge 400 can vary a flow cross-section to the tank outlet T1. At the second web 302, the aforementioned second throttle restriction 271 is provided, which leads to the tank outlet T1.

6 shows the uniformly arranged on the circumference Materialausnehmungen 250, 251, 252. The second working port B has an inner ring groove 480, one edge 481 together with an edge 254 or 255 or 256 of the respective

Material recess 250, 251, 252 forms the second flow cross-section.

The second throttle point 271 is basically less effective than the first throttle point 308. In the second throttle point 271 of the hollow piston 219 namely pressure balanced, since the pressurizable annular surface on the second web 302 is a pressurizable surface on a third web 41 1 opposite. Without this second throttle point, however, the hollow piston would 219 when opening the second working port B to the first tank drain T1 relatively abruptly in

Direction to the electromagnet 300 are torn. However, the second throttle point causes a delay, so that the hydraulic valve is easier to control.

The central screw 405 has a seal 481 on which the first

Working port A seals against the second working port B.

There must be no ram provided. The hollow piston can also rest directly on an armature of the electromagnet.

Instead of the helical compression spring for the hollow piston or the

Helical compression springs for the check valves can also disc springs

Find application.

The rotor 8 may in an alternative embodiment by means of a

Compensating spring against the stator 1 to be biased torsionally elastic.

The described embodiments are only exemplary embodiments. A combination of the described features for

different embodiments is also possible. Further, in particular not described features of the device parts belonging to the invention are to be taken from the geometries of the device parts shown in the drawings.

Claims

claims

1 . Pivot camshaft phaser (14) with an electromagnetically actuated hydraulic valve (12), the one by means of an electromagnet (100) along

slidably in a bore (85) used hollow piston (19) for distribution of hydraulic fluid to two pressure chambers (9, 10) of the Schwenkmotornockenwellenverstellers (14) associated working ports (A, B), wherein of the bore (85) of the first working port (A) immediately adjacent to the electromagnet (100), wherein the hollow piston (19) has a circumferential web (102) with a control edge (107) facing the electromagnet (100), so that a space (103) within the bore (85 ) on the one hand from the web (102) and

on the other hand is delimited by the electromagnet (100), wherein the space (103) leaves a drain opening (104) which hydraulically connects the space (103) with a drainage channel (105) leading to a tank drain (T), wherein the bridge (102) by means of a force (FM) of the energized electromagnet (100) in a first

Working port (A) in the flow cross-section (106) widening direction

is displaceable, said force (FM) is a spring force (FF) directed against, which presses the web (102) in the flow cross-section (106) decreasing direction, wherein the web (102) is provided a throttle point (108) between the flow cross-section (106) and the space (103) is arranged, wherein the web (102) closes the flow cross-section (106) when the hollow piston (19) due to the spring force (FF) in de-energized electromagnet (100) in a

End position is shifted.

2. Schwenkmotornockenwellenversteller (14) according to claim 1, characterized in that the drain opening (104) between the web (102) and the electromagnet (100) in the hollow piston (19) is provided, wherein these

Drain opening (104) hydraulically connects the space (103) with the outflow channel (105) leading to the tank outlet (T) within the hollow piston (19).

3. Schwenkmotornockenwellenversteller according to claim 1, characterized in that the bore (385) in a central screw (405) with a screw head (404) extends, in the region of the drain opening (304) is provided.

4. Schwenkmotornockenwellenversteller according to claim 3, characterized

characterized in that the drainage channel (305) forms between the screw head (404) and the electromagnet (300).

5. Schwenkmotornockenwellenversteller (14) according to claim 1, characterized in that a housing part (121) of the electromagnet (100) is fixedly connected to a component, in which the bore (85) is incorporated.

6. Schwenkmotornockenwellenversteller (14) according to claim 1, characterized in that the throttle point (108) as the web (102) subsequent annular gap (1 14) is executed.

7. Schwenkmotornockenwellenversteller (14) according to claim 1, characterized in that the electromagnet (100) has a plunger (20) which rests against the hollow piston (19) and is guided through an opening in the pole core (122).

8. Schwenkmotornockenwellenversteller according to claim 1, characterized

characterized in that the restriction (308) is limited in circumference

Matrialausnehmung (270) from the web (302) is executed.

9. Schwenkmotornockenwellenversteller according to claim 8, characterized

characterized in that a plurality of such circumferentially limited Matrialausnehmungen (270) are provided on the circumference of the web (302), wherein the first

Working connection (A) has an inner ring groove (401), whose one inner edge (253) together with a control edge (272) of the respective material recess (270) forms the flow cross-section.

10. Schwenkmotornockenwellenversteller according to one of the preceding

Claims, characterized in that the first working port (A) between the second working port (B) and the electromagnet (300) is arranged, wherein the hollow piston (219) has a second circumferential rib (302) facing away from the electromagnet (300) Control edge (400), which may vary a flow cross section to the tank outlet (T1), wherein on the second web (302) a second throttle point (271) is provided, which to the

Tank drain (T1) leads.

1 1. Schwenkmotornockenwellenversteller according to one of the preceding

Claims, characterized in that the throttle point (108, 308) in each position of the hollow piston (19, 219) to the space (103, 303) is permanently open, but the throttle point (108)

- With decreasing force (F-M) of the electromagnet (100) due to the spring force (F-F) up to an end position of the hollow piston (19) of

- A the solenoid (100) facing the control edge (107, 272) of the web (102, 302) and

- One of the first working port (A) associated inner edge (192, 253) relative to the first working port (A) is closable.

12. Schwenkmotornockenwellenversteller according to one of the preceding

Claims, characterized in that one of the throttle point (108, 308) to the space (103, 303) leading hydraulic path (199, 399) remains open regardless of how far in the direction of the electromagnet (100, 300) hinfort of the hollow piston (19 , 219) is moved.