EP2501905B1 - Switchable pressure supply device - Google Patents

Description

Field of the invention

The invention is in the technical field of internal combustion engines and relates to a switchable device for supplying pressure to at least one consumer of an internal combustion engine.

State of the art

From the patent EP 1197641 A2 a pressure accumulator for supporting a hydraulically adjustable camshaft is known, in which a pressure medium flow in or out of the pressure accumulator is controlled by using different solenoid valves.

The German patent application DE 102007056684 A1 the applicant shows a pressure accumulator with its own housing.

Furthermore, the German Offenlegungsschrift describes DE 10228354 A1 a built-in an internal cavity of a camshaft pressure accumulator, which space can be saved in the internal combustion engine.

Object of the invention

In contrast, the object of the present invention is to further develop conventional pressure accumulator for supplying pressure to consumers in an internal combustion engine in an advantageous manner.

Solution of the task

These and other objects are achieved according to the proposal of the invention by a switchable device for supplying pressure with the features of the main claim. Advantageous embodiments of the invention are indicated by the features of the subclaims.

According to the invention, a switchable device for supplying pressure (switchable pressure accumulator) to at least one consumer of an internal combustion engine is shown. The consumer may in particular be a hydraulic camshaft adjuster for adjusting the phase angle between crankshaft and camshaft. However, it is also conceivable that the device is used for example in an electro-hydraulic valve actuating device of the internal combustion engine.

The pressure supply device comprises a housing with a cavity. The cavity may, for example, be an internal cavity of a camshaft so that the camshaft forms the housing of the switchable device. Alternatively, a different from the hollow camshaft housing may be provided with a cavity, which is then inserted into an inner cavity of the camshaft.

The device for pressure supply further comprises a housing arranged in the cavity displacement element which is displaceable between a first end position and a second end position. The displacement element has a pressure surface which, together with a wall of the housing cavity, at least partially delimits a reservoir which can be connected or connected to the load in a fluid-conducting manner. The storage space can be fluid-conductively connected or connected to a pressure or pressure medium source. For example, the storage space is connected to the lubricating oil circuit of the internal combustion engine, wherein an oil pump serves as a pressure source and oil of the lubricating oil circuit is used as a pressure medium. The displacement element can, for example be formed in the form of a piston with a frontal pressure surface.

The device according to the invention further comprises a force accumulator which cooperates with the displacement element so that the displacement element can be displaced from the first end position into the second end position by pressurizing the reservoir against the force of the force accumulator. The energy accumulator is designed for example as a spring element, in particular in the form of a compression spring, wherein any other suitable spring type can be used.

The device according to the invention further comprises a locking mechanism, by means of which the displacement element can be releasably locked in the second end position in which the force accumulator is tensioned. In a different position of the displacement element from the second end position, in particular in the first end position, the displacement element can not be locked by the locking mechanism.

Furthermore, the device according to the invention comprises an actuated by an actuator switching mechanism with a switching element, which can be brought into at least two switching positions, wherein the switching element cooperates with the locking mechanism, that the displacement element in a first switching position of the switching element from both an unlocked state locked can also be unlocked from a locked state and in a second switching position of the switching element in the unlocked state neither locked nor unlocked in the locked state.

The inventive device allows for a comparatively small space requirement, a reliable and secure pressure supply to consumers of an internal combustion engine, which is independent of the pressure in the lubrication circuit of the internal combustion engine available.

In an advantageous embodiment of the device according to the invention, this comprises a rigidly connected to the housing ball carrier element with a carrier cavity in which the switching element is at least partially accommodated. In this case, the ball carrier element has a plurality of openings, in each of which a ball is received radially movable. The balls are applied to an outer circumferential surface formed by the switching element. In this embodiment of the device, the device further comprises a locking element rigidly connected to the displacement element, which is provided with a locking portion, which can reach the second end position of the displacement element in engagement with the balls, for example by this engages behind, thereby the displacement element on the housing to lock. On the other hand, in the first end position of the displacement element, the locking element can not engage with the balls, so that the displacement element is not locked. In this embodiment of the device further comprises a return element is provided, which is arranged so that the switching element is displaceable relative to the force of the return element by the actuator from the first switching position to the second switching position relative to the ball carrier element. The first return element is formed, for example, as a spring element, in particular in the form of a compression spring, wherein any other suitable spring type can be used. In this embodiment of the device, the outer circumferential surface of the switching element is provided with at least one recess associated with the balls, which is formed and arranged so that the balls can be at least partially received in the recess in the second switching position of the switching element, so that the locking portion disengaged arrives with the balls and the locking of the displacement element is released. On the other hand, the balls are not received by the recess of the support surface in the first switching position of the switching element, so that the locking of the displacement element is maintained.

These measures allow a technically particularly simple realization of the device according to the invention, which is characterized by a particularly good response.

In the above embodiment of the invention may also be advantageous if a rigidly connected to the ball carrier element fuse element is arranged, which forms a stop for a radially outwardly directed movement of the balls, such that the balls are taken secured against loss in the openings. In a technically simple realization of the securing element this is cup-shaped and applied from one side to the ball carrier element. In this case, the securing element and the ball carrier element can be rigidly connected to each other, for example by pressing. By the securing element thus a captive for the balls is created when they are not in engagement with the locking portion of the locking element.

In a further advantageous embodiment of the device according to the invention for supplying pressure, the latter is provided with a closing element closing off the cavity to the outside, on which the force accumulator of the displacement element is supported. The closure element can serve in particular for securing the position of the force accumulator. In this case, it may also be advantageous if the ball carrier element is rigidly connected to the closure element. In addition, it may be advantageous if the closure element is provided with a passage opening in which a cooperating with the switching element, actuated by the actuator switch body is received displaceably. By these measures, the device according to the invention can be technically realized in a particularly simple manner.

In a further advantageous embodiment of the device according to the invention, the storage space can be fluidly connected or connected to the pressure source and possibly the consumer with the interposition of at least one outlet safety device. The leakage protection is designed so that it allows the flow of pressurized pressure medium, whereas it blocks the flow of non-pressurized, only the hydrostatic pressure underlying the pressure medium. Thus, by the leakage protection leakage of the storage space in the absence of a pressure feed be prevented by the pressure source, for example, in the absence of promotion of the oil pump. The leakage protection can serve as a limitation of the storage space and can in particular form a stop for the displacement element in the first end position. The structure of such leakage protection is known in the art and in the patent literature, for example in the DE 19615076 described.

In a further advantageous embodiment of the device according to the invention, the pressure source via a blocking in the direction of the pressure source check valve with the reservoir space fluidly connected or connected.

The invention further extends to an internal combustion engine which is equipped with at least one switchable device as described above for supplying pressure to at least one consumer.

Brief description of the drawings

Fig. 1

eine schematische Axialschnittdarstellung mit vergrößertem Ausschnitt eines Ausführungsbeispiels der erfindungsgemäßen Vorrichtung zur Druckversorgung;

Fig. 2

eine schematische Übersichtsdarstellung, anhand derer der Anschluss der Vorrichtung zur Druckversorgung von Fig. 1 an den Schmierölkreis einer Brennkraftmaschine veranschaulicht ist;

Fig. 3A-3C

vergrößerte Axialschnittdarstellungen zur Veranschaulichung der Verriegelung der Vorrichtung zur Druckversorgung von Fig. 1;

Fig. 4A-4C

vergrößerte Axialschnittdarstellungen zur Veranschaulichung der Entriegelung der Vorrichtung zur Druckversorgung von Fig. 1.

The invention will now be explained in more detail with reference to an embodiment, reference being made to the accompanying drawings. Identical or equivalent elements are denoted by the same reference numerals in the drawings. Show it:

Fig. 1

a schematic axial sectional view with enlarged detail of an embodiment of the device according to the invention for pressure supply;

Fig. 2

a schematic overview representation, by which the connection of the device for pressure supply of Fig. 1 to the lubricating oil circuit of an internal combustion engine is illustrated;

Figs. 3A-3C

enlarged axial sectional views to illustrate the locking of the device for pressure supply of Fig. 1 ;

Fig. 4A-4C

enlarged Axialschnittdarstellungen to illustrate the unlocking of the device for pressure supply of Fig. 1 ,

Detailed description of the drawings

Be first Fig. 1 and Fig. 2 considered, wherein an embodiment of the inventive device for supplying pressure to consumers of an internal combustion engine, and the connection of the device to the lubricating oil circuit of an internal combustion engine are illustrated. The device generally designated by the reference numeral 1 can be inserted into a camshaft cavity 5 of a hollow camshaft 6. The camshaft 6 constructed here, for example, which is provided on its outer peripheral surface with a plurality of cams 25, can be rotated about a central axis of rotation 7. Equally, however, it would also be conceivable that the camshaft 6 is produced by forging.

The device 1 for supplying pressure to consumers of an internal combustion engine comprises a hollow cylindrical housing 2 ("cartridge"), which is formed in a manner adapted to the camshaft cavity 5, so that the device 1 can be easily integrated into the camshaft 6 by the housing 2 in the camshaft cavity 5 is introduced and firmly connected to the camshaft 6.

The housing 2 forms a housing cavity 3, in which a displacement element designed in the form of a piston 4 is received in an axially displaceable manner. In the housing cavity 3 further formed in the form of a stepped cylinder closure body 7 is pressed, which extends from one end of the housing 2 ago in the housing cavity 3 inside. It may be divided into a larger diameter terminal first section 8 and an adjoining second smaller diameter section 9, thereby forming an annular step 10. At the ring stage 10 is a force accumulator serving as energy storage spring (helical compression spring) 11 with its one end, which abuts the piston 4 with its other end.

The firmly connected to the housing 2 closure body 7 is provided with a central axial bore 12 in which a shift rod 13 is received axially displaceable. The shift rod 13 can be actuated by an electromagnetic actuator 14, for which purpose a non-illustrated plunger engages a front-side abutment surface of the shift rod 13. The shift rod 12 is part of a switching mechanism for locking and releasing a locking mechanism for the piston 4, which will be explained in more detail below. The piston 4 has an end-face pressure surface 15 which, together with a housing cavity wall 16 of the housing cavity 3, at least partially delimits a reservoir 17 for pressurized oil.

Opposite to the actuator 14, a hydraulic camshaft adjuster 18 is fastened, for example by means of a (not shown) central screw on the end face of the camshaft 6. As usual, the hydraulic camshaft adjuster 18 comprises a driven part which is drivingly connected to the crankshaft and a camshaft-fixed driven part, as well as a hydraulic actuator connected between driving and driven part, which transmits the torque from the to the driven part and an adjustment and fixation of the Rotary position between these allows. The hydraulic actuator is provided with at least one oppositely acting pressure chamber pair, which is specifically acted upon by pressure oil, to bring about a change in the rotational position between the input and output part by generating a pressure gradient across the two pressure chambers. Hydraulic camshaft adjusters as such are well known to those skilled in the art and for example in the documents DE 202005008264 U1 . EP 1596040 A2 . DE 102005013141 A1 . DE 19908934 A1 and WO 2006/039966 The applicant described in detail, so that it need not be discussed in more detail here.

Like the overview of Fig. 2 can be removed, the hydraulic camshaft adjuster 18 and the reservoir 17 are fluidly connected via a pressure line 19 with a formed in the form of an oil pump 20 pressure or pressure medium source. In this case, the pressure line 19 is connected to opening into the camshaft cavity 5 radial openings 26 of the camshaft 6. Thus, by the oil pump 20 pressure oil from an oil tank 21 to the camshaft adjuster 18 and reservoir 17 are transported. A non-return valve 22 arranged in the pressure line 19, which blocks in the direction of the oil pump 20, prevents a return of pressurized oil at a reduced or missing delivery rate of the oil pump 20.

In the central screw for fixing the camshaft adjuster 18 on the camshaft 6, a not-shown control valve for controlling the oil flows is arranged, through which the Druckkammem the camshaft adjuster 18 can be fluidly connected to the oil pump 20 or with the oil tank 21. Such control valves are well known in the art as such and for example in the German patent DE 19727180 C2 , the German patent DE 19616973 C2 , the European patent application EP 1 596 041 A2 and the German Offenlegungsschrift DE 102 39 207 A1 The applicant described in detail, so that it need not be discussed in more detail here.

In the device 1, the storage space 17 communicates with the hydraulic camshaft adjuster 18 or its control valve. In addition, other consumers are connected to the lubricating oil circuit, such as support members 23 and bearings 24 of the camshaft 6, which must be supplied with pressure oil. Although this is not shown in the figures, a leakage protection for limiting the storage space 17 may be provided, which may serve in particular as a stop for the piston 4.

In the device 1, the piston 4 can be displaced axially by pressurizing the storage space 17 against the spring force of the energy storage spring 11 by pressure oil from the oil pump 20 via the pressure line 19 in the storage space 17 is promoted. In this case, the piston 4 is moved from a first end position to a second end position, in which the energy storage spring 11 is stretched or more tensioned in the presence of a bias voltage. About not shown ring seals the reservoir 17 is closed to the outside oil-tight.

In the second end position, the piston 4 can be locked by a locking mechanism. The locking mechanism comprises a sleeve-shaped ball carrier 31, which is pressed into a cup-shaped end section 27 of the closure body 7 and has a plurality of radial bores 29 distributed in the circumferential direction, in each of which a ball 30 is accommodated. The holes 29 each have a larger diameter than the balls 30, so that they are radially freely movable in the holes 29. The ball carrier 28 is rigidly connected to the closure body 7.

On the closure body 7 opposite free end portion of the ball carrier 28 is a cup-shaped fuse body 31, consisting of a bottom wall 33 and a hollow cylindrical sleeve member 32, pressed. In this case, the sleeve part 32 of the securing body 31 is dimensioned such that it partially covers the radial bores 29 with a certain projection, so that only a certain radially outward movement of the balls 30 is made possible. Beyond that, radially outwardly directed movement of the balls 30 is blocked by the sleeve part 32, so that the balls 30 each remain received in the bores 29.

In a carrier cavity 34 of the ball carrier 28 is coupled to the axially displaceable shift rod 13 switching pin 35 is received axially displaceable. The switching pin 35 has a first end face 36, which is coupled to a front end of the shift rod 35. In carrier cavity 34, a return spring 39 is further included, with one end to one of the first end face 37 opposite the second end face 37 of the switch pin 35 and with its other end to an inner surface 38 of Bottom wall 33 of the fuse body 31 is supported. The return spring 39 is formed here, for example, as a helical compression spring, but may also be of any other suitable spring type. The shift pin 35 can thus be moved axially by moving the shift rod 13 by the plunger of the actuator 14 against the spring force of the return spring 39. In this case, the plunger acts on the front-side abutment surface of the shift rod 13, wherein the plunger is rigidly secured to a magnet armature of an electromagnet of the actuator 14 and can be moved axially by energizing the magnet armature. If the magnet armature is not energized, the switching pin 35 is reset by the spring force of the return spring 39.

An outer circumferential surface 40 of the switching pin 35 is provided with a circumferential annular groove 41, which is assigned to the balls 30 and formed in a fit to the balls 30. The switching pin 35 can be moved back and forth between two end positions by the counteracting forces of actuator 14 and return spring 39. In a first end position without energization of the actuator 14, the balls 30 are outside the annular groove 41. In a second end position with energized actuator 14, the balls 30 can dip into the annular groove 41. Always the balls 30 of the outer circumferential surface 40 of the switch pin 35, so that they are taken in connection with the fuse body 31 secured against loss in their holes 29.

On the piston 4, a locking body 42 is pressed. The locking body 42 is provided for this purpose with an applied to the cup-shaped piston 4 hollow cylindrical sleeve portion 43 to which a locking portion 44 connects. The sleeve portion 43 serves for axial guidance of the piston 4 within the housing cavity 3. The locking portion 44 tapers stepwise in the direction of the actuator 14 back. In this case, a first step 45 tapering towards the actuator 14 forms an annular support surface 47 for the energy storage spring 11. An adjoining, second step 46 tapering towards the actuator 14 forms an annular seating surface 48 for the balls 30. One to the second Level 46 molded Collar 52, which widens radially with respect to the second step 46, forms a contact surface 49 for the balls 30.

An unlocking of the piston 4 of the device 1 will now be described, with reference to the Figures 3A-3E is taken.

If the reservoir 17 is acted upon by the oil pump 20 with pressure oil, the piston 4 is moved over its pressure surface 15 against the spring force of the energy storage spring 11 until the contact surface 49 of the locking body 42 comes to rest against the balls 30. If the actuator 14 is not actuated, the shift pin 35 is reset by the spring force of the return spring 39. In this position of the switching pin 35, the balls 30 are outside the annular groove 41. In this case, the locking portion 44 of the locking body 42 is sufficiently resistant to deformation, so that it can not slide over the balls 30 away. This situation is in Fig. 3A shown.

If the actuator 14 is actuated by energizing the electromagnet, the shift rod 13 is moved against the force of the return spring 39 by the plunger acting on the face-side abutment surface. In this case, the shift pin 35 is brought by the shift rod 13 into a position in which annular groove 41 is radially inwardly of the holes 29 and balls 30, so that the balls 30 can dip into the annular groove 41. Thus, the balls 30, urged by the locking portion 44, are pressed into the annular groove 41. The depth of the annular groove 41 is dimensioned such that the piston 4 or the locking portion 44 rigidly connected to the piston 4 can be displaced even further against the spring force of the energy storage spring 11. For example, the balls 30 are completely received within the holes 29 and close at least approximately flush with an outer circumferential surface of the ball carrier 28 from. This situation is in Fig. 3B shown.

If the piston 4, acted upon by the pressure oil in the storage space 17, is further displaced counter to the spring force of the energy storage spring 11, finally an end-face abutting surface 50 of the locking body 42 arrives An end position (referred to in the introduction as "second end position") of the piston 4 is defined, in which the storage space 17 is filled to the maximum with pressure oil. If the actuator 14 is no longer actuated, that is, the energization of the electromagnet is terminated, the shift pin 35 is axially displaced by the spring force of the return spring 39 relative to the ball carrier 28, wherein the balls 30 are pressed from the annular groove 41 against the seat surface 48 of the locking portion 44 , In this position, the locking portion 43 engages behind the balls 30, so that the piston 4 is axially fixed. This situation is in Fig. 3C shown.

The piston 4 can thus be locked against the spring force of the return spring 39 from the first switching position to the second switching position in its second end position only by pressing the plunger to move the switching pin 35. Without displacement of the switching pin 35 in the second switching position, the piston 4 can not be locked.

Will now, starting from a locked piston 4, as in Fig. 3C shown, the actuator 14 actuated by repeated energization of the electromagnet, the shift rod 13 is moved by the acting on the front-side abutment surface plunger against the force of the return spring 39. In this case, the shift pin 35 is brought by the shift rod 13 in the second switching position, in which annular groove 41 is radially inwardly of the holes 29 and balls 30, so that the balls 30 can dip into the annular groove 41. The balls 30 are then, acted upon by the spring force of the energy storage spring 11, via the locking portion 44, pressed into the annular groove 41. This has the consequence that the locking portion 44, the balls 30 no longer engages behind and the locking of the piston 4 is released. This situation is in Fig. 3D shown.

This has the consequence that the piston 4 is displaced by the spring force of the energy storage spring 11, wherein pressure oil is discharged from the reservoir 17 to the hydraulic camshaft adjuster 18. The piston 4 is, acted upon by the spring force, moved until it abuts against one of strikes by the spring force, displaced until it comes to rest against a formed by the camshaft 6 stop 53, whereby an end position of the piston 4 is defined (referred to in the introduction to the introduction as "first end position"). A movement of the piston 4 between the two end positions corresponds to a maximum piston stroke of the piston 4, through which the ejected maximum volume is given. Alternatively, a leakage protection could serve as an end stop for the piston 4.

The piston 4 can thus be unlocked by pressing the plunger to move the switch pin 35 against the spring force of the return spring 39 from the first switching position to the second switching position. Without displacement of the switching pin 35 in the second switching position, the piston 4 can not be unlocked.

In the device according to the invention can thus be biased by a separate housing in a cavity of the camshaft piston by the pressure of the oil pump with the engine running against the energy storage spring up to a specified stroke. In this position, the piston engages by a short energizing the radially decoupled actuator, which is mounted outside the camshaft, in a holding mechanism (ball lock). When the internal combustion engine is switched off, the oil pressure in the oil galleries falls to ambient pressure, as does the pressure in the pressure accumulator. The energy remains stored in the energy storage spring. An optional leakage protection means that the "pressure-free" lubricating oil can not run back from the storage room into the oil galleries or via the camshaft bearing points into the cylinder head. As a leakage protection, for example, a lamellar labyrinth leakage protection, consisting of three sheets, each with a bore in the axial direction on the outer diameter. The sheets are rotated by 120 ° to each other. The pressure accumulator has no pressure loss due to leaks. Elaborate high pressure seals omitted. As a result, the system friction is reduced and stored more usable energy in the energy storage spring. On the other hand, by briefly energizing the actuator, the locking mechanism of the piston can be released. By means of the prestressed energy storage spring For example, the oil from the reservoir is forced back into the oil circuit of the cylinder head and the phaser, provided that the supply oil pressure in the oil galleries is less than the pressure achievable with the accumulator (spring element force multiplied by piston pressure area). In order to prevent backflow of the oil in the direction of the oil pump during unloading, a non-return valve in the direction of the oil pump is provided between the oil pump and the consumers, which are to be acted upon by oil pressure from the pressure accumulator.

In the device according to the invention, the piston is guided axially in the housing and is supported by a spring element (eg tension or compression spring) on the closure body, which is pressed into the housing. In the closure body of the ball carrier is pressed. This has, for example, eight radial bores, in each of which a ball is guided. The shift rod is coupled to the shift pin and mounted axially displaceable in the closure body. The actuator is screwed, for example, in the cylinder head and presses in the energized state on the shift rod against the return spring of the switch pin. The connection to the shift rod / camshaft via a radial decoupling. The fuse body serves as a captive for the balls. The arrangement in the cavity of the camshaft results in a space advantage over externally arranged camshaft pressure accumulators.

The device according to the invention enables a reliable pressure supply to consumers of an internal combustion engine, wherein pressure oil is independent of the engine oil supply (lubricating oil circuit) of the internal combustion engine available through the integrated pressure accumulator in the camshaft. Thus, consumers can be supplied with pressurized oil even if the engine-side oil supply is insufficient, for example, at engine start and very hot pressure oil in conjunction with a low flow rate of the oil pump (hot idle). In particular, immediately after the start of the engine, an adjustment of the camshaft adjuster in basic position (late, middle, early position) take place, which is particularly suitable in connection with Start / stop systems is. In addition, the adjustment speed of the camshaft adjuster can be improved, in particular when the internal combustion engine is idling. The device according to the invention can be realized by relatively few components, which can be saved in industrial mass production assembly and material costs. A particular advantage of the device results from the fact that the piston can be locked or unlocked by briefly energizing the actuator (current pulses). A permanent energization of the actuator in the locked or unlocked state of the piston is not required. This allows a particularly energy-saving operation of the device for pressure supply.

LIST OF REFERENCE NUMBERS

1

contraption

2

casing

3

housing cavity

4

piston

5

camshafts cavity

6

camshaft

7

closure body

8th

first section

9

second part

10

annular step

11

Power storage spring

12

axial bore

13

shift rod

14

actuator

15

print area

16

Housing cavity wall

17

pantry

18

Phaser

19

pressure line

20

oil pump

21

oil tank

22

check valve

23

supporting

24

depository

25

cam

26

radial opening

27

end

28

ball carrier

29

drilling

30

Bullet

31

fuse body

32

sleeve part

33

bottom wall

34

carrier cavity

35

switch pin

36

first end face

37

second end face

38

palm

39

Return spring

40

Outer casing surface

41

ring groove

42

locking body

43

sleeve section

44

locking section

45

first stage

46

second step

47

support surface

48

seat

49

contact surface

50

Impact surface of the locking body

51

Impact surface of the closure body

52

collar

53

attack

Claims (15)

1. Switchable device (1) for supplying pressure to at least one consumer of an internal combustion engine, which device comprises:

   a housing (2) with a housing cavity (3),

   a displacement element (4) which is arranged in the housing cavity (3) and which is displaceable between a first end position and a second end position, the displacement element (4) being provided with a pressure surface (15) which, together with a housing cavity wall (16), delimits at least partially a storage space (17) connectable in a fluid-conducting manner to the consumer, the storage space (17) being connectable in a fluid-conducting manner to a pressure source (20),

   a force accumulator (11) cooperating with the displacement element (4), the displacement element (4) being displaceable, counter to the force of the force accumulator (11), from the first end position to the second end position by the action of pressure upon the storage space (17),

   a locking mechanism, by means of which the displacement element (4) can be locked in the second end position,

   a switching mechanism actuable by means of an actuator (14) and having a switching element (35) which can be brought into at least two switching positions and which cooperates with the locking mechanism such that the displacement element (4) is lockable or unlockable in a first switching position of the switching element (35) and is non-lockable or non-unlockable in a second switching position of the switching element (35).
2. Pressure supply device (1) according to Claim 1, characterized by:

   a ball carrier element (28) connected rigidly to the housing (2) and having a carrier cavity (34), in which the switching element (35) is at least partially accommodated, the ball carrier element (28) having a plurality of orifices (29), in each of which a ball (30) is accommodated in a radially movable manner, the balls (30) bearing against an outer surface area (40) formed by the switching element (35),

   a locking element (42) which is connected to the displacement element (4) and is provided with a locking portion (44) which can come into engagement with the balls (30) in order to lock the displacement element (4) in its second end position,

   the switching element (35) being displaceable in relation to the ball carrier element (28), counter to the force of a restoring element (39), by the actuator (14) from the first switching position into the second switching position, and

   the outer surface area (40) of the switching element (35) being provided with at least one recess (41), in such a way that, in the second switching position, the balls (30) can be accommodated at least partially by the recess (41), so that the locking portion (44) comes out of engagement with the balls (30).
3. Pressure supply device (1) according to Claim 2, characterized by a closing element (7) which is connected rigidly to the housing (2) and on which the force accumulator (11) of the displacement element (4) is supported.
4. Pressure supply device (1) according to Claim 3, characterized in that the ball carrier element (28) is connected rigidly to the closing element (7).
5. Pressure supply device (1) according to either one of Claims 3 and 4, characterized in that the closing element (7) is provided with a through-orifice (12), in which a switching body (13) cooperating with the switching element (35) and actuable by the actuator (14) is accommodated displaceably.
6. Pressure supply device (1) according to one of Claims 2 to 5, characterized by a securing element (31) which is connected rigidly to the ball carrier element (28) and which forms a stop for a radially outward-directed movement of the balls (30), in such a way that the balls (30) are accommodated captively in the orifices (29).
7. Pressure supply device (1) according to Claim 6, characterized in that the securing element (31) is of pot-shaped form and is attached to the ball carrier element (28) from one side.
8. Pressure supply device (1) according to one of Claims 1 to 7, characterized in that the force accumulator is designed as a spring element (11).
9. Pressure supply device (1) according to one of Claims 1 to 8, characterized by a housing (2) insertable into a cavity (5) of a camshaft (6).
10. Pressure supply device (1) according to one of Claims 1 to 8, characterized in that the housing (2) is formed by a camshaft (6) and the housing cavity (3) is formed by a cavity (5) of the camshaft (6).
11. Pressure supply device (1) according to one of Claims 1 to 10, characterized in that the storage space (17) is connectable in a fluid-conducting manner to the pressure source (20) via an outflow safeguard for pressure medium, which outflow safeguard which is permeable on the action of pressure and which blocks without the action of pressure.
12. Pressure supply device (1) according to Claim 11, characterized in that the outflow safeguard serves as a boundary for the storage space (17).
13. Pressure supply device (1) according to one of Claims 1 to 12, characterized in that the pressure source (20) is connectable in a fluid-conducting manner to the storage space (17) via at least one non-return valve (22) which blocks in the direction of the pressure source.
14. Pressure supply device (1) according to one of Claims 1 to 13, characterized in that oil from the lubricating oil circuit is used as pressure medium.
15. Internal combustion engine, with at least one switchable device (1) for supplying pressure to a consumer according to one of Claims 1 to 14.

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