Vane-type camshaft adjuster system

Abstract

The object of the invention is to provide an economical vane-type camshaft adjuster system that meets the various requirements of various motors. For this purpose, according to the invention a modular system is provided for the valves of a vane-type camshaft adjuster system. Two different embodiments of valves are proposed. With one embodiment, a valve with mid-locking and without mid-locking may be constructed using the same bush. With the other embodiment, a valve with and without special utilization of the camshaft alternating torques may be constructed using the same bush.

Description

This application claims the benefit of German patent application no. DE 10 2009 022 869.1 filed on May 27, 2009, which is incorporated herein and made a part hereof by reference for all purposes.

BACKGROUND OF THE INVENTION

The invention relates to a vane-type camshaft adjuster system.

From DE 10 2004 039 800 B4 a vane-type camshaft adjuster system for a drive motor is already known. Such a vane-type camshaft adjuster comprises a rotor having five vanes, which are disposed circumferentially between radially inwardly directed webs of a stator. The vanes divide in each case one pressure chamber into two hydraulic chambers working in opposite directions. One pressure chamber of these five pressure chambers has a spring-loaded locking pin, which is aligned parallel to a central axis. When this locking pin is situated in a locking position, the rotor is then fixed relative to the stator in an intermediate position lying between “early” and “late” end positions.

Locking in such an intermediate position that is neither the “early” end position nor the “late” end position is generally also referred to as mid-locking even if this mid-locking is not effected exactly mid-way between the two end positions.

The two hydraulic chambers of the vane-type camshaft adjuster according to DE 10 2004 039 800 B4 are controllable by means of an electrohydraulic 4/4-way valve having a magnet part as an actuator. For this purpose the valve has:

• • a first working port A for the first hydraulic chamber,
  • a second working port B for the second hydraulic chamber,
  • a tank port T and
  • a supply port P.

Upon starting of the drive motor, by means of the 4/4-way valve in a first state through simultaneous interconnection of the two working ports the two hydraulic chambers are relieved to an unpressurized state relative to the tank port T. In this unpressurized state the locking pin may move into the locking position. The 4/4-way valve in this case is of a cartridge style of construction. It comprises a bush, inside which a hollow piston is guided in an axially displaceable manner. For this purpose the piston has at the one end a cup base, which is supported under spring loading against an electromagnetically displaceable tappet of the magnet part. The bush has three recesses disposed axially adjacent to one another. The piston on the other hand has circumferential annular control grooves. By displacing the axial position of the annular control grooves relative to the three recesses, a hydraulic fluid coming from the supply port P is conveyed towards the two working ports A, B and/or towards the tank port T.

DE 103 44 816 B4 relates to a further vane-type camshaft adjuster system for a drive motor. This reference discloses a cartridge-style 6/4-way valve which likewise comprises a bush and a piston disposed inside the bush. The 6/4-way valve has a separate position for removing hydraulic fluid from the two hydraulic chambers so that two spring-loaded locking devices may lock in an intermediate position that is neither the “early” end position nor the “late” end position. These two locking devices are radially aligned and disposed in a web of the stator. One of the three ports of the 6/4-way valve is associated exclusively with the two locking devices.

From DE 10 2006 012 733 B4 and/or DE 10 2006 012 775 B4 a vane-type camshaft adjuster system having a 4/3-way valve is known. This valve is of a cartridge style of construction. Inserted into the bush at the inside are non-return valves that take the form of band-shaped rings. By means of these non-return valves, camshaft alternating torques are utilized to allow the camshaft adjuster to be adjusted particularly quickly and/or with a relatively low oil pressure.

From DE 44 22 742 C2 an electrohydraulic valve is already known, which comprises:

• • a supply port P,
  • a first working port A,
  • a second working port B and
  • a tank port T.

The valve is of a cartridge style of construction and comprises a bush having three recesses. Inside the bush a hollow piston is axially displaceable along a running surface. For this purpose there is provided at one piston end a cup base, which is supported under spring loading against a displaceable tappet of an electromagnetic actuator. The piston has a circumferential annular control groove. Provided at the two piston ends are outflow recesses, which are aligned transversely of a central axis of the valve and lead to the tank port T. Provided on the piston, adjacent to the magnet-side outflow recess, is a circumferential rib, past which a hydraulic flow may be conveyed from the magnet-side working port to the outflow recess.

The object of the invention is to provide an economical vane-type camshaft adjuster system that meets the various requirements of various motors.

This and other objects are achieved according to the present invention.

SUMMARY OF THE INVENTION

The present invention provides a modular system for the valves of a vane-type camshaft adjuster system. Two different embodiments of valves are proposed. With one example embodiment, a valve with mid-locking and without mid-locking may be constructed using the same bush. With another example embodiment, a valve with and without special utilization of the camshaft alternating torques may be constructed using the same bush.

According to the present invention, one example embodiment of a valve of the vane-type camshaft adjuster system is disclosed, which enables mid-locking with an economical valve. The valve may have details developed in a constructionally identical manner for a vane-type camshaft adjuster system with utilization of the camshaft alternating torques.

According to one advantageous aspect of the invention, it is at the piston end facing the magnet part (i.e. the magnet-side piston end) that an outflow recess leading to the tank port T and aligned transversely relative to the central axis is provided. On the other hand, the other end is designed as a piston-terminating control edge for directing hydraulic fluid to the tank port T. This, on the one hand, achieves cost benefits as the piston therefore has to be provided with relatively few recesses—in particular transverse bores. The piston may also be of a relatively short design, thereby allowing a saving of material not only at the piston but also at the bush. Furthermore, a helical compression spring for spring-loading the piston towards a tappet of the magnet part may be of a relatively short design as this helical compression spring may be supported relatively close to the piston end. The short overall length of the 4/4-way valve also offers advantages in terms of installation space.

In a further advantageous manner the bush and the piston according to the present invention are designed in such a way that it is possible to create a design family of valves for vane-type camshaft adjusters that enables only slight design variations between the valves. These valves may be:

• • a 4/4-way valve with a special outflow position for the mid-locking, but without non-return valves for special utilization of the camshaft alternating torques;
  • a 4/4-way valve with a special outflow position for the mid-locking and with non-return valves for special utilization of the camshaft alternating torques;
  • a 4/3-way valve without a special outflow position for the mid-locking and with non-return valves for special utilization of the camshaft alternating torques; and
  • a 4/3-way valve without a special outflow position for the mid-locking and without non-return valves for special utilization of the camshaft alternating torques.

In particular the magnet parts of such valves be of an identical design. The pistons of a valve without mid-locking need differ from the pistons with mid-locking only in that in the more complex variant with mid-locking:

• • on the one hand a middle outer web is provided, which divides the annular groove into two annular grooves, and
  • on the other hand a magnet-side outer web is divided by means of an annular groove into two outer webs.

For the constructional realization, there is provided on the piston, adjacent to the outflow recess, a circumferential rib, past which a hydraulic flow coming from the magnet-side working port B may be conveyed to the outflow recess. Furthermore, between the magnet part and the second working port B, a region having an inside diameter that is widened relative to the running surface is provided, thereby forming between this inside diameter and the running surface a run-off edge that is blockable by the rib. Thus, by virtue of the fact that a circumferential rib always forms the run-off edge relative to the recess of the working port B, the piston need not be installed angularly oriented relative to the bush. For this reason, it is also possible to dispense with an anti-rotation element between the bush and the piston and hence reduce costs. If, however, the outflow recess were directly to form the run-off edge relative to the recess of the second working port B, an expensive angular orientation would be necessary. The solution according to the invention comprising a circumferential rib for blocking/releasing of the outflow recess to the piston, on the other hand, makes it possible to allow the piston to run directly along the running surface that is penetrated by the recess for the working port B. The same applies to the embodiment (as described in the previous paragraph) of the other piston end as a control edge. This spring-side piston end may also slide directly along the running surface in the region of the recess which penetrates this running surface of the first working port A, with the result, at this piston end too, that the piston requires no angular orientation and/or anti-rotation element. The running surface may therefore inexpensively take the form of a bore passing through the entire running region. The internal machining of the running surface may in this case be carried out by a high-quality surface treatment.

In this case, in an advantageous manner the inside diameter of the bush in the axial region between the magnet part and the outer web positioned closest thereto may be designed with an inside diameter that is widened relative to the running surface. For the external machining of the bush it is therefore possible to clamp the bush tightly in a tool, for example a three-jaw chuck, without the bush being plastically deformed to such an extent that the running surface becomes inoperative.

Further advantages of the invention emerge from the claims, the detailed description and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will hereinafter be described in conjunction with the appended drawing figures, wherein like reference numerals denote like elements, and:

FIG. 1 shows an example embodiment of a vane-type camshaft adjuster in accordance with the present invention,

FIG. 2 shows a sectional representation of a 4/4-way valve in a first example embodiment of the present invention,

FIG. 3 a sectional representation of the hydraulic part along line II-II of FIG. 1,

FIG. 4 a hydraulic diagram of the 4/4-way valve of FIG. 2 and FIG. 3,

FIG. 5 shows the hydraulic part of the valve of FIG. 2 in a first position,

FIG. 6 shows the hydraulic part according to FIG. 5 in a second position,

FIG. 7 shows the hydraulic part in a third position,

FIG. 8 shows the hydraulic part in a fourth position,

FIG. 9 shows the piston of the 4/4-way valve of FIG. 2 to FIG. 8 as a single part in a perspective view,

FIG. 10 shows another piston for a valve of a vane-type camshaft adjuster system in a second example embodiment of the present invention,

FIG. 11 shows a 4/3-way valve having the piston according to FIG. 10,

FIG. 12 shows a sectional representation of the hydraulic part of the 4/3-way valve along line XII-XII of FIG. 11,

FIG. 13 shows a hydraulic diagram of the 4/3-way valve of FIG. 11 and FIG. 12,

FIG. 14 to FIG. 16 show, in views similar to that of FIGS. 2-4, a third example embodiment of a hydraulic part for an electrohydraulic 4/4-way valve of a vane-type camshaft adjuster system in accordance with the present invention, and

FIG. 17, FIG. 18 and FIG. 19 show, in views similar to that of FIGS. 2-4, a fourth example embodiment of a the hydraulic part for an electrohydraulic 4/3-way valve of a vane-type camshaft adjuster system in accordance with the present invention.

DETAILED DESCRIPTION

The ensuing detailed description provides exemplary embodiments only, and is not intended to limit the scope, applicability, or configuration of the invention. Rather, the ensuing detailed description of the exemplary embodiments will provide those skilled in the art with an enabling description for implementing an embodiment of the invention. It should be understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the invention as set forth in the appended claims.

In accordance with an example embodiment of the present invention as shown in FIG. 1, by means of a vane-type camshaft adjuster during operation of a combustion-engine drive motor the angular position between a crankshaft, which is not represented in detail, and a camshaft 127 is varied. In this case, by rotating the camshaft 127 the opening and closing times of the gas exchange valves are shifted in such a way that the combustion-engine drive motor produces its optimum output and/or best possible exhaust gas emissions for the respective rotational speed. The vane-type camshaft adjuster in this case enables a stepless adjustment of the camshaft 127 relative to the crankshaft. The vane-type camshaft adjuster has a cylindrical stator 101, which is connected in a rotationally fixed manner to a gearwheel, which is not represented in detail. This gearwheel may be for example a sprocket wheel, over which a chain extends. The gearwheel may however alternatively be a toothed-belt wheel, over which a drive belt extends as a drive element. By means of this drive element and the gearwheel the stator 101 is in a known manner drive-connected to the crankshaft.

The stator 101 comprises a cylindrical stator basic body 103, from the inside of which webs 104 project radially inwards at uniform intervals over the circumference. Formed between adjacent webs 104 are pressure chambers 105, into which pressure medium is introduced. The introduction of this pressure medium is effected in a controlled and/or regulated manner by means of a 4/4-way valve and/or 4/3-way valve in accordance with the present invention that is described below in connection with the figures. Protruding between adjacent webs 104 are vanes 106, which project radially outwards from a cylindrical rotor basic body 107 of a rotor 108. These vanes 106 subdivide the pressure chambers 105 between the webs 104 in each case into two hydraulic chambers 109 and 110.

The webs 104 lie with their end faces sealingly against the outer lateral surface of the rotor basic body 107. The vanes 106 in turn lie with their end faces sealingly against the cylindrical inner wall of the stator basic body 103.

The rotor 108 is connected in a rotationally fixed manner to the camshaft 127. In order to vary the angular position between the camshaft 127 and the crankshaft, the rotor 108 is rotated relative to the stator 101. For this purpose, depending on the desired direction of rotation the pressure medium in the first hydraulic chambers 109 and/or 110 is pressurized, while the second hydraulic chambers 110 and/or 109 are relieved in the direction of the tank.

The rotor 108 is positively fixable in a rotationally fixed manner relative to the stator 101. For this purpose a locking pin 121 is provided, which is aligned parallel to a central axis 125 of the vane-type camshaft adjuster. This locking pin 121 is preloaded by a small compression spring and in a locking position of the rotor 108 relative to the stator 101 may engage into a location hole 126 of the stator 101. This location hole 126 lies, in terms of the circumference, in an intermediate position between the “early” and “late” end positions.

FIG. 2 shows a partial section of a proportionally adjustable 4/4-way valve 81, which in this embodiment is used for the adjustment of the camshaft of a combustion-engine drive motor having a vane-type camshaft adjuster.

In this case, the 4/4-way valve 81 takes the form of a cartridge valve. This cartridge valve comprises a hydraulic part 83 and a magnet part 5. The hydraulic part 83 has a piston 13 and a bush 15. The piston 13 runs inside the bush 15 along the running surface 85 thereof. The piston 13 is preloaded by means of a helical compression spring 9, which is supported relative to a support ring 11 on the bush 15. The bush 15 is provided with openings 86, 87, 88, which in the illustrated case are rotationally symmetrical bores. These openings 86, 87, 88 represent the first working port A, the second working port B and the supply port P. The arrows indicate the regular oil directions. At the end face of the hydraulic part 83 a central opening 17 is provided for the tank port T. This tank port T lies at right angles to the other three ports A, B and P of the 4/4-way valve 81. The opening 17 for the tank port T lies centrally inside the support ring 11. The helical compression spring 9 encircles this opening 17 for the tank port T. The piston 13 is hollow. The piston 13 is provided with outflow recesses 21, which at the magnet-side piston end establish the connection to the hollow space 89 of the piston 13. In and around the 4/4-way valve 81 a series of seals are mounted, which during operation keep the hydraulic fluid away from the environment and from the parts not supplied with hydraulic fluid. In this case, the seal 25 as a magnet-part seal seals off the magnet part 5 from the hydraulic part 83. The tappet 41, which rests against a cup base 93 of the piston 13, is a tappet 41 that is preloaded with hydraulic fluid and situated in the hydraulic fluid. A pole seal 63 and a non-visible coil seal ensure that the hydraulic fluid situated in the magnet part 5 cannot escape outside, i.e. outside of a housing 27. The housing 27 at its side close to the hydraulic part 83 verges into a flange 29 that is provided with fastening openings, i.e. the fastening bores 31. The pole core 39 succeeding the hydraulic part 83 is connected by beads 33 to the housing 27. These beads 33 are disposed in the region of the pole seal 63. Inside the housing 27 a coil, an armature, the pole core 39 and the tappet 41 are disposed. For further details about the magnet part 5 reference is made to DE 10 2004 039 800 B4, which in this regard is to be regarded as incorporated by reference in this application.

The armature in this case may be moved to and fro between two armature chambers, which are in fluidic communication with the hydraulic part 83 of the 4/4-way valve 81 when the piston 13 is outside of its end stop position.

On the opposite end of the housing 27 to the opening 17 for the tank port T an electric plug 47 is fastened.

A tappet oil space 77 is connected by the outflow recesses 21 to the central opening 17 for the tank port T. This connection of the hydraulic part 83 to the magnet part 5 of the 4/4-way valve 81 is established by means of an edge-formed portion 23. This edge-formed portion 23 is attached laterally to the bush 15.

In the non-energized state of the magnet part 5, the piston 13 blocks off the rear hydraulic channel (coming from armature chambers) in the magnet part 5 from the tank port T. The helical compression spring 9 then experiences no counterforce and is in its outspread, most extended and relaxed position. All of the hydraulic fluid from the hydraulic chambers 110, 109 of the vane-type camshaft adjuster escapes through the opening for the tank port T. Via:

• • corresponding outer webs 50, 51, 52, 53 on the piston 13,
  • corresponding inner edges 54, 55 in the bush 15,
  • the inner circumferential edges 56, 57 of the openings 88, 86 of the working ports A, B and
  • the outflow recess 21,
    the ports A and B are in hydraulic communication with the opening 17 for the tank port T. Placed in front of the openings 86, 87, 88 of the bush 15 are filters 42, 43, 44, which ensure that the 4/4-way valve 81 functions also in the event of contaminated hydraulic fluid.

The inside diameter of the bush 15 in the axial region between the magnet part 5 and a shoulder 34 is designed with an inside diameter that is widened relative to the running surface 85. This shoulder 34 lies approximately at the outer web 50 positioned closest to the magnet part 5. For the external machining of the bush 15 it is therefore possible to clamp the bush 15 tightly in a three-jaw chuck without the bush 15 being plastically deformed to such an extent that the running surface 15 becomes inoperative.

From FIG. 3 it is evident that for producing the four openings 86 the bush 15 is provided with two bores aligned orthogonally relative to one another. The same applies to the openings 87, 88 of the bush 15, which are not visible in FIG. 3.

FIG. 4 shows the 4/4-way valve 81 in a schematic view. If the coil of the magnet part 5 is energized with a first, clearly defined current, the piston 13 moves out of a first position 1 into a second position 2. If the coil is moreover loaded with a stronger current and/or a higher duty factor of the pulse width modulation, the piston 13 moves into the third position 3. Upon an increase to the strongest defined current, the piston 13 moves into the fourth position 4. In practice, the positioning of the piston 13 from position 2 via position 3 to position 4 is not stepped. Instead, the volumetric flows rise and/or fall in proportion to the current strength and/or the duty factor.

FIG. 5 shows, as in FIG. 2 and FIG. 4, the hydraulic part 83 in a first position 1, in which upon disconnection, stopping or starting of the drive motor through simultaneous hydraulic interconnection of the two working ports A, B the two hydraulic chambers 110, 109 are relieved to an unpressurized state relative to the tank port T, so that the locking pin 121 visible in FIG. 1 moves into the locking position and/or into the location hole 126. The activation of the coil in this case has such a duty factor that the piston 13 is displaced by a stroke of between 0 and 0.2 mm counter to the action of the helical compression spring 9. The supply port P is closed in the direction of the working ports A, B by the middle outer web 52 and the outer web 53 disposed on the spring-side piston end 90. On the other hand, the hydraulic flow from the working port A along the outer web 53 to the tank port T is open. In this case, the hydraulic fluid at the spring-side piston end 90 runs via a circumferential control edge 96 to the tank port T. The hydraulic flow from the working port B along an annular groove 91 between the two outer webs 50, 51, which are positioned close to the magnet part 5, to the tank port T is likewise open.

FIG. 6 shows the hydraulic part 83 in the second position 2. In this case, the activation of the coil has such a duty factor that the piston 13 is displaced by a stroke of between 0.2 and 0.8 mm counter to the action of the helical compression spring 9. In this case, the supply port P, starting from a stroke of 0.2 mm, begins to open for a hydraulic flow to the second working port B. On the other hand, the hydraulic flow from this second working port B to the tank port T is closed because the hydraulic pressure is closed by the outer web 50 positioned closest to the magnet part. The hydraulic flow from the working port A along the outer web 53 to the tank port T is open.

FIG. 7 shows the hydraulic part 83 in the third position 3. In this case, the activation of the coil has such a duty factor that the piston 13 is displaced counter to the action of the helical compression spring 9 into a middle position, which lies at a stroke of 1.8 mm. In this case, the supply port P is closed in the direction of the two working ports A, B by the middle outer web 51 and the outer web 53 disposed at the spring-side piston end 90. Equally, the hydraulic flow from the second working port B to the tank port T is closed because the hydraulic pressure is closed by the outer web 50 positioned closest to the magnet part. The hydraulic flow from and to the first working port A is blocked because the outer web 53 at the spring-side piston end 90 is longer in axial direction than the opening 88 of the first working port A, with the result that the entire opening 88 is overlapped.

FIG. 8 shows the hydraulic part 83 in the fourth position 4. In this case, the activation of the coil has such a duty factor that the piston 13 is displaced counter to the action of the helical compression spring 9 into a maximum end position, which lies at a stroke of 3 mm. In this case, the supply port P is open in the direction of the first working port A. On the other hand, the hydraulic flow from the second working port B to the tank port T is open, wherein the hydraulic fluid flows along the outer web 50 that is situated at the outermost magnet-side piston end 92.

FIG. 9 shows the piston 13 of the 4/4-way valve 83 of FIG. 2 to FIG. 8 as a single part in a perspective view.

FIG. 10 shows another piston 213 for a vane-type camshaft adjuster system in a second example embodiment. This vane-type camshaft adjuster system however, in contrast to the previous example embodiment vane-type camshaft adjuster system, has no mid-locking. Nevertheless the differences between the two pistons 13, 213 in relation to their overall manufacturing process are very small. For instance, in contrast to the piston 13 with mid-locking the piston 213 without mid-locking does not have an approximately centrally disposed outer web 52. Furthermore, instead of the two magnet-side outer webs 50, 51 only a single outer web 151 is provided. This single outer web 151, in terms of the axial delimitations 98, 99, has the axial delimitations 98, 99 of the piston 13 with mid-locking. However, in contrast to the piston 13 with mid-locking, an annular groove 91 is not provided. Otherwise the two pistons 13, 213 are of an identical type of design.

FIG. 11 shows a 4/3-way valve having the piston 213 according to FIG. 10. The piston 213 runs inside the bush 15 along the running surface 85 thereof. The bush 15 according to this embodiment is in this case of an identical design to the bush 15 according to the other embodiment according to FIG. 2 to FIG. 9.

From the diagram according to FIG. 13 it is however evident that the 4/3-way valve of FIG. 11 and FIG. 12 is designed as a 4/3-way valve. In this case, the 4/3-way valve has the three positions 2, 3, 4 and is proportionally controllable.

The flow from the supply port P to the first working port A and/or the second working port B is accordingly controllable in proportion to the current. In this case, just as in the 4/4-way valve according to FIG. 4, there is a position 3, in which via the run-off edges 200, 201 according to FIG. 11 a minimal hydraulic pressure is applied to the two hydraulic chambers 109, 110 working in opposite directions.

The constructionally identical design of the bushes in the case of the use of different pistons to realize a vane-type camshaft adjuster system in accordance with the present invention, with and without a special outlet position for the mid-locking, may be used also in vane-type camshaft adjuster systems with special utilization of camshaft alternating torques, such as is described for example in DE 10 2006 012 733 B4.

In this regard FIG. 14 to FIG. 16 show in a further example embodiment the hydraulic part 283 for an electrohydraulic 4/4-way valve of a vane-type camshaft adjuster system having a central axis 225. In this example embodiment, in contrast to FIG. 2 to FIG. 4, no filters are provided in front of the openings 286, 288 of the two working ports A, B. In the base of the annular grooves 260, 261 associated with these two working ports A, B, however, further openings 262, 263 are provided for utilization of the camshaft alternating torques. In contrast to the openings 286, 288 that are exclusively blockable from inside by the outer webs 250, 251, 253, the further openings 286, 288 have band-shaped non-return valves 270, 271. In each case a band-shaped non-return valve 270 and/or 271 is inserted into an inner annular groove 274 and/or 275 radially inside of the further opening 262 and/or 263 of the bush 215. By means of these non-return valves 270, 271 it is possible in accordance with the method described in DE 10 2006 012 733 B4 for a hydraulic pressure, which in the hydraulic chamber 109 and/or 110 to be relieved rises because of camshaft alternating torques for a short time above the level of the hydraulic pressure in the hydraulic chamber 110 and/or 109 to be loaded, to be made available in the region of the supply port P. From this supply port P this hydraulic pressure peak and/or this additional hydraulic fluid flow is then made available, together with the hydraulic pressure applied up by an oil pump 272 (visible in FIG. 16) to the supply port P, to the hydraulic chamber 110 and/or 109 that is to be loaded.

In this case, a third band-shaped non-return valve 276 is additionally provided in an inner annular groove 277. This third non-return valve 276 is however a pump protection valve, which is basically of an identical construction to the two non-return valves 270, 271. This pump protection valve may however have a different response force.

In an alternative example embodiment of the present invention according to FIG. 14, filters are inserted also in the annular grooves 260, 261.

FIG. 17, FIG. 18 and FIG. 19 show in a fourth example embodiment the hydraulic part 383 for an electrohydraulic 4/3-way valve of a vane-type camshaft adjuster system. This vane-type camshaft adjuster system however, in contrast to the third example embodiment of FIG. 14 to FIG. 16, has no mid-locking. In this case, the same bush 215 is used as in the third example embodiment. The piston 313 however differs from the piston 213 according to the third example embodiment. Furthermore, the annular groove 291 for the tank port T between the two outer webs 250, 251 that is shown in FIG. 14 is not provided. Instead, the single outer web 351 is not divided into two outer webs 250, 251 but is of an integral construction. In terms of the axial delimitations 298, 299, this single outer web 351 accordingly has the axial delimitations 298, 299 of the piston 13 with mid-locking. A further difference from the third example embodiment is that an axially approximately middle outer web 252 is not provided.

The previously described valve design embodiments are not limited to proportional valves but may be used also in on-off valves.

Depending on the operating conditions of the valve, filters may be provided in front of all of the openings to protect the running surfaces between piston and bush.

The hydraulic part of the illustrated valves may also be used in a so-called master valve. In this case, the bush is not connected directly to the magnet part. Instead, the hydraulic part is disposed centrally in the rotor of the vane-type camshaft adjuster so that the bush rotates jointly with the piston. The magnet, on the other hand, is disposed in a rotationally fixed manner relative to the cylinder head so that a relative movement occurs between the tappet of the magnet part and the piston.

The described forms of construction are merely exemplary embodiments. A combination of the described features for different forms of construction is equally possible. For example, a set of valves may be provided which includes different embodiments of valves and pistons described herein. Such a set of valves may have a modular construction. Further, in particular non-described features of the device parts belonging to the invention are to be gathered from the geometries of the device parts that are represented in the drawings.

Claims

1. Vane-type camshaft adjuster system for a drive motor, comprising:

a rotor having at least one vane that divides a pressure chamber formed circumferentially between two radially inwardly directed webs of a stator into two hydraulic chambers working in opposite directions,

a locking pin associated with said pressure chamber, which locking pin is aligned parallel to a central axis and which in a locking position fixes the rotor relative to the stator in an intermediate position lying between “early” and “late” end positions,

an electrohydraulic 4/4-way valve for controlling the two hydraulic chambers, the 4/4-way valve comprising: a supply port (P), a first working port (A) for the first hydraulic chamber, a second working port (B) for the second hydraulic chamber, and a tank port (T),

by means of the 4/4-way valve in a first position (1) during disconnection, stopping or starting of the drive motor through simultaneous hydraulic interconnection of the two working ports (A, B), the two hydraulic chambers being relieved to an unpressurized state relative to the tank port (T) so that the locking pin moves into the locking position, the 4/4-way valve being of a cartridge style of construction and comprising a bush, which is provided with three openings disposed axially adjacent to one another and inside which a hollow piston is axially displaceable along a running surface, and a cup base which is provided at the magnet-side piston end, which cup base is supported under spring loading against a displaceable tappet of a magnet part, the piston comprising:

two circumferential annular control grooves,

an outflow recess at the magnet-side piston end leading to the tank port (T) and aligned transversely of the central axis, and

a circumferential outer web adjacent to said outflow recess, past which a hydraulic flow may be conveyed from the second working port (B) to the outflow recess, said circumferential outer web at the spring-side piston end takes the form of a circumferential control edge for directing hydraulic fluid to the tank port (T).

2. Vane-type camshaft adjuster system according to claim 1, wherein an inner running surface of the bush is drilled in one diameter in a region of the openings associated with the two working ports (A, B).

3. Vane-type camshaft adjuster system according to claim 2, wherein an inside diameter of the bush in an axial region between the magnet part and the outer web positioned closest thereto is designed with an inside diameter that is widened relative to the running surface.

4. Vane-type camshaft adjuster system according to claim 1, wherein the recess associated with the supply port (P) is provided axially between the openings associated with the working ports (A, B).

5. Vane-type camshaft adjuster system for a drive motor, comprising:

a rotor having at least one vane that divides a pressure chamber formed circumferentially between two radially inwardly directed webs of a stator into two hydraulic chambers working in opposite directions,

an electrohydraulic 4/4-way valve for controlling the two hydraulic chambers, the 4/4-way valve comprising: a first working port (A) for the first hydraulic chamber, a second working port (B) for the second hydraulic chamber, a supply port (P) disposed in relation to a central axis between said two working ports (A, B), and a tank port (T),

the 4/4-way valve being of a cartridge style of construction and comprising a bush, which is provided with at least four openings disposed axially adjacent to one another, of which a first and a second opening are associated with the one of the two working ports (B and/or A), of which the first opening positioned closer to the supply port (P) is provided with a non-return valve, by means of which hydraulic fluid is directed from the first hydraulic chamber associated with said one working port (B and/or A) through the other working port (A and/or B) to the second hydraulic chamber associated with said other working port (A and/or B) when: the second opening is closed by a hollow piston, and camshaft alternating torques raise the hydraulic pressure in the first hydraulic chamber above the hydraulic pressure inside the bush,

inside said bush the piston being axially displaceable along a running surface and at the magnet-side piston end a cup base is provided, which is supported under spring loading against a displaceable tappet of a magnet part,

wherein the piston comprises: at least one circumferential annular control groove, an outflow recess at the magnet-side piston end leading to the tank port (T) and aligned transversely of the central axis, and a circumferential outer web adjacent to said outflow recess, past which a hydraulic flow may be conveyed from the spring-side working port (B) to the outflow recess, said circumferential outer web at the spring-side piston end takes the form of a circumferential control edge for directing hydraulic fluid to the tank port (T).

6. Vane-type camshaft adjuster system according to claim 5, wherein an inner running surface of the bush is drilled in one diameter in a region of the openings associated with the two working ports (A, B).

7. Vane-type camshaft adjuster system according to claim 6, wherein an inside diameter of the bush in an axial region between the magnet part and the outer web positioned closest thereto is designed with an inside diameter that is widened relative to the running surface.

8. Vane-type camshaft adjuster system according to claim 5, wherein the recess associated with the supply port (P) is provided axially between the openings associated with the working ports (A, B).

9. Set of valves for a vane-type camshaft adjuster system for a drive motor, comprising:

at least two types of valves, each valve comprising: a first working port (A) for a first hydraulic chamber, a second working port (B) for a second hydraulic chamber, a supply port (P), and a tank port (T), an identical magnet part, an identical bush, and one of a piston with mid-locking and a piston without mid-locking,

wherein:

the piston with mid-locking comprises: two circumferential annular control grooves, an outflow recess at a magnet-side piston end leading to the tank port (T) and aligned transversely of a central axis, and a circumferential outer web adjacent to said outflow recess, past which a hydraulic flow may be conveyed from the second working port (B) to the outflow recess, said circumferential outer web at a spring-side piston end takes the form of a circumferential control edge for directing hydraulic fluid to the tank port (T); and

the piston without mid-locking comprises: at least one circumferential annular control groove, an outflow recess at a magnet-side piston end leading to the tank port (T) and aligned transversely of the central axis, and a circumferential outer web adjacent to said outflow recess, past which a hydraulic flow may be conveyed from a spring-side working port (B) to the outflow recess, said circumferential outer web at the spring-side piston end takes the form of a circumferential control edge for directing hydraulic fluid to the tank port (T).

10. A set of valves according to claim 9, further comprising:

at least one rotor having at least one vane that divides a pressure chamber formed circumferentially between two radially inwardly directed webs of a stator into the two hydraulic chambers working in opposite directions.

11. A set of valves according to claim 9, wherein the valve with the mid-locking piston further comprises:

a locking pin associated with said pressure chamber, which locking pin is aligned parallel to a central axis and which in a locking position fixes the rotor relative to the stator in an intermediate position lying between “early” and “late” end positions; and

wherein by means of the valve in a first position (1) during disconnection, stopping or starting of the drive motor through simultaneous hydraulic interconnection of the two working ports (A, B), the two hydraulic chambers being relieved to an unpressurized state relative to the tank port (T) so that the locking pin moves into the locking position.

12. A set of valves according to claim 9, wherein:

each bush is provided with at least three openings disposed axially adjacent to one another and inside which the piston is axially displaceable along a running surface, and

a cup base is provided at the magnet-side piston end, which cup base is supported under spring loading.

13. A set of valves according to claim 12, wherein, in the valve with the piston without mid-locking, camshaft alternating torques raise the hydraulic pressure in the first hydraulic chamber above the hydraulic pressure inside the bush.