EP1544420A2 - Internal combustion engine with hydraulic camshaft phasing device - Google Patents

Abstract

The device has a rotor (6) with blades (10) fastened to the camshaft (2), and a stator (4) with end wall (5) fastened to a drive pulley (3) driven by the crankshaft. The stator, esp. its web walls, and its inner and outer peripheral walls, is a metal plate or band part, formed by a non-cutting process. The stator has local reinforcements of profiles, beads, etc. extending along direction of special loads. Stator, outer stator housing (13), and drive pulley are fastened to each other by e.g. forming technology. Pressure chambers between stator and rotor are closed at one end by a metal sealing plate (14). Hollows or cutouts in stator walls are filled with metal foam or injected plastic.

Description

Field of the invention

The invention relates to an internal combustion engine with a hydraulic device for the rotational angle adjustment of a camshaft with respect to a crankshaft, comprising: a rotor with wings arranged thereon, the non-rotatable with the camshaft is connected, a frontally provided with an end wall Stator rotatably with a driven by the crankshaft drive wheel is connected, provided on both sides of the wing pressure chambers are, in each case by web walls and inner and outer, in the circumferential direction, are concentric walls of the stator are limited and pressurizable via a hydraulic system with hydraulic fluid or be emptied.

Background of the invention

From DE 101 34 320 A1 an internal combustion engine with a generic hydraulic device for adjusting the angle of rotation of a camshaft known, the phase angle of a camshaft relative to a crankshaft can change. This device consists of a rotor and a stator, of which the former, designed as an impeller, the camshaft includes and turns in sync with her. The stator is on the one hand by an end wall, which Part of a housing surrounding the stator, and on the other hand closed by a drive wheel fluid-tight. It includes the rotor and rotates synchronously with the driven by the crankshaft drive wheel. Essentially radially extending web walls in the stator allow only one limited rotational angle of the rotor and form with this several pressure chambers, which can be pressurized with hydraulic fluid or emptied.

1. eine hohe Masse der Vorrichtung zur Drehwinkelverstellung,

2. hohe Fertigungskosten durch den Zerspanungsaufwand bei der Fertigung der Sinterbauteile,

3. eine unerwünschte, externe Ölleckage durch die porösen Sinterbauteile.

A disadvantage of this known device, however, is that the items of the device mainly consist of steel or iron, which are made by sintering or machining. This results

1. a high mass of the device for adjusting the rotational angle,

2. high production costs due to the machining outlay during the production of the sintered components,

3. undesirable external oil leakage through the porous sintered components.

Because in the sintered metallurgy thin wall thicknesses, especially in context with wall thickness variations in terms of density distribution as well Strength and rigidity are problematic and continue to be complex shapes with different filling heights often only with expensive sliders in the To implement tools are previous devices for the rotation angle adjustment usually made of relatively heavy and solid components. At cutting manufactured devices, the problem is similar; complicated, The load adapted forms are with high machining costs connected.

A proposal for reducing the mass of the device for adjusting the angle of rotation For example, DE 101 48 687 A1 or DE 101 34 320 A1 be removed by parts of the device made of aluminum or a Made of aluminum alloy or another light metal. This has the disadvantage that by different thermal expansion coefficients the leakage gaps can increase over the warming and thus one high leakage results. In addition, aluminum is deformed with the same dimensions under load stronger than steel or iron. Especially if then the Individual parts must be clamped together by housing screws correspondingly large column allow a deformation. The housing screws represent an increased construction cost, thus causing higher costs and also result in a non-optimal power flow for the device.

Object of the invention

The invention is therefore based on the object, a device for rotational angle adjustment a camshaft relative to a crankshaft for a To design an internal combustion engine such that on the one hand a mass reduction the device takes place on the other hand, while minimizing the Leakage.

Description of the invention

According to the invention, the object is in a device for an internal combustion engine solved with the features of the preamble of claim 1 thereby that essential parts of the stator, in particular its web walls and its inner and outer walls, and optionally the housing with a possibly arranged therein sealing disc as non-cutting produced sheet metal parts are formed. Of course, instead of sheet metal also used band be used in the following sheet as a generic term for sheet metal or tape becomes.

The solid sintered components as pressure chamber forming units of the drive side are thus replaced by thin-walled sheet metal and Blechumformteile. Because fewer sintered components must be manufactured, this results in a Reduction of cutting costs and reduction of external costs Oil leakage by eliminating the porous sintered parts.

Thus, the device despite its lower mass high rigidity and Resilience, these sheets can be local, along the load directions by formations or corresponding profiles ideally the load be adapted without requiring larger wall thicknesses globally and thus a high mass must be accepted. Across from a Massereduktion by using light metal such as proposed in DE 101 34 320 A1, this has the advantage that the thermal expansion coefficient All components remain the same and thus no leaks due to thermal effects.

The stator consists of inner and outer circumferentially extending Walls and web walls. The web walls each connect two ends from adjacent inner and outer circumferentially Walls and extend substantially radially. For some stator variants it is advantageous if the web walls are not exactly radial, but one have certain angles to the radial or they are not flat, but recesses, for example, jamming of the wings in their final positions.

Because the stator is made of thin-walled sheet metal, it is not so dimensionally stable like a sintered stator known in the art. It exists the possibility of the stator directly via cohesive connection options to attach to the torque transmitting component. To a comparable To achieve bending and compression stiffness like that of the sintered stator, but he can be used in a comprehensive housing him (Figure 2a), which with connection technologies of the forming technology or by general force, shape and friction-locked technologies such as knurling, Flanging, welding, caulking, riveting, gluing or bent retaining lugs is connected to the drive wheel. The housing then takes over the Connection of the stator to the drive wheel as torque transmitting and Radial load-transferable component and the seal. It also prevents that occur at the stator due to introduced radial forces vibrations.

The housing seals the stator on one end face and forms one there Bulkhead. If the stator walls to the end wall no right angle form, the sealing of the pressure chambers is not completely guaranteed. To avoid leakage losses, it is therefore advantageous to use a sealing washer immediately before the front wall, so that after connecting the front wall with the stator and inserting the rotor with wings rectangular Pressure chambers arise. The stability of the housing can be additionally increased when you connect the sealing disc firmly to the front wall. The Sealing disk is preferably profiled from thin-walled sheet metal and in size and shape of the stator adapted.

The cohesion of the parts stator, housing and sealing disc is through above-mentioned joining technologies of forming technology ensured. Compared to the axial, non-positive screw connection are compressive stress deformations reduced; In addition, advantageously no additional Component needed and reduced assembly costs.

It is expedient to form the non-cutting parts made of metal strips. If necessary, as in the case of the stator, the strip must be at one point formed a ring and then firmly connected, for example by Welding. The non-cutting production of the stator and the housing means of course not that these parts are not post-machined if very high accuracy is required.

A second way to increase the bending and compressive stiffness of the stator, is to make the web walls so that they radial forces and / or Can transmit peripheral forces (Figure 3a). The support of the radial chain or belt power can be internally between stator and rotor or externally between Camshaft or an extension of the rotor and sprocket or made from a combination of both possibilities. It's special here proven advantageous to form the web walls not exactly radially, but in a range of 10 ° to 30 ° to the radial, so that the wings in their end positions touch the radially outer web wall ends.

A third embodiment is a tubular stator whose web walls as retracted Webs are formed. Through the remaining, closed ring surface the housing is saved. This further reduces the mass. Between edge and the radially extending walls, the sealing disc inserted and then sealed the edge and firmly connected. At this Execution takes up the ring surface on the radial forces and prevents Swinging of the stator.

To achieve better formability, the radially extending Walls should also be designed as open ends, in which case for storage and Seal used in the rotor sliding shoes. The sliding shoes are like that trained and arranged that they trained as retracted webs Support web walls against each other. They prevent bending the web walls.

The spaces between the web walls, either cavities or cuts, are plastic-injected or sprayed or foamed metal. As a result, the profile of the substantially radially extending Web walls stiffened and a high tightness of the pressure chambers with each other as well as externally ensured.

The wall thickness of the radially extending walls of the stator can be further reduced be prevented if the wings of the rotor are prevented in their respective Strike end positions against the radially extending walls of the stator and put pressure on them. For this purpose, a Verstellwinkelbegrenzung is necessary. This can for example via a related to the rotor Element for Verstellwinkelbegrenzung that in a corresponding backdrop engages, be realized.

The inventively designed device is thus opposite a device The prior art lighter, requires less cutting costs and thus reduces the manufacturing costs and can also be applied to a synthetic resin impregnation or steam treatment for sealing the now refrain from using any sintered material that is no longer required.

Brief description of the drawings

Figur 1

einen Längsschnitt einer Vorrichtung zur Drehwinkelverstellung, wobei ein spanlos ausgebildeter Stator in einem Außengehäuse eingesetzt ist;

Figur 2

einen Querschnitt durch eine Vorrichtung zur Drehwinkelverstellung,

Figur 3

einen Querschnitt einer zweiten Ausführung eines Stators,

Figur 4a

einen Querschnitt einer dritten Ausführung eines Stators,

Figur 4b

eine perspektivische Ansicht des Stators gemäß Figur 4a,

Figur 5a

einen Querschnitt einer vierten Ausführung eines Stators, dessen äußere Ringfläche geschlossen ist,

Figur 5b

eine perspektivische Ansicht des Stators gemäß Figur 5a,

Figur 6a

eine perspektivische Ansicht auf eine äußere, in Umfangsrichtung verlaufende Wand und nach außen ausgeformte Stegwände einer fünften Ausführung eines Stators

Figur 6b

eine perspektivische Ansicht auf eine äußere, in Umfangsrichtung verlaufende Wand und nach innen ausgeformte Stegwände einer sechsten Ausführung eines Stators mit einem Gleitschuh.

The invention will be explained in more detail with reference to embodiments and shown schematically in the accompanying drawings.
Show it

FIG. 1

a longitudinal section of a device for adjusting the rotational angle, wherein a chipless formed stator is inserted in an outer housing;

FIG. 2

a cross section through a device for adjusting the rotational angle,

FIG. 3

a cross section of a second embodiment of a stator,

FIG. 4a

a cross section of a third embodiment of a stator,

FIG. 4b

a perspective view of the stator according to Figure 4a,

FIG. 5a

a cross section of a fourth embodiment of a stator whose outer annular surface is closed,

FIG. 5b

a perspective view of the stator according to Figure 5a,

FIG. 6a

a perspective view of an outer, circumferentially extending wall and outwardly shaped web walls of a fifth embodiment of a stator

FIG. 6b

a perspective view of an outer, circumferentially extending wall and inwardly molded web walls of a sixth embodiment of a stator with a sliding block.

Detailed description of the drawings

From Figures 1 and 2 go the essential parts of a hydraulic Device 1 for adjusting the angle of rotation of a camshaft 2 with respect to a not shown crankshaft, which is designed as a hydraulic actuator is. This device 1 is driven by a drive wheel 3, for example connected by a chain not shown with the crankshaft is, driven. In essence, the device 1 consists of a fixed with the drive wheel 3 connected to the stator 4, by an end wall 5 and the Drive wheel 3 is sealed fluid-tight, and one by an axial Central screw 21 rotatably connected to the camshaft 2 rotor 6, wherein the rotor 6 is designed as an impeller. The stator 4 of the device 1 formed by web walls 7, 7 ', 7 "and by outer 8, 8', 8" and inner 9, 9 ', 9 ", circumferentially extending walls with the rotor 6 and its wings 10 first pressure chambers 11, 11 ', 11 "and second pressure chambers 12, 12', 12", which, filled with hydraulic fluid, an angular adjustment between the rotor. 6 and stator 4. The rotor 6 and the stator 4 are in a housing 13th arranged, the first 11, 11 ', 11 "and second 12, 12', 12" pressure chambers seals to the outside. By a standing with the rotor 6 in connection Element 16 for Verstellwinkelbegrenzung, which in a corresponding Setting 17 engages, is carried out limiting the adjustment of the rotor 6, which reduces the loads on the stator 4.

For the purpose of sealing the pressure chambers 11, 11 ', 11 ", 12, 12', 12" is between Housing 13 and stator 4, a sealing washer 14 is inserted, which corresponds to the diameter of the stator 4 is adjusted.

In Figure 2, the web walls 7, 7 ', 7 "are not exactly formed radially, but at an angle of about 20 °, so that the wings 10 in their end positions the radially outer ends of the web walls 7, 7 ', 7 "touch the bending and compressive rigidity of the stator 4 increases and it is possible radial forces and to transmit circumferential forces

FIG. 3 shows a cross section of a second version of a tube Stators 4. It forms by its substantially radially extending Web walls 7, 7 ', 7 "and its inner 8, 8', 8" and outer 9, 9 ', 9 ", in the circumferential direction extending walls with the not shown in this figure Rotor 6, the first 11, 11 ', 11 "and second 12, 12', 12" pressure chambers. Of the Stator 4 itself is arranged in a cylindrical housing 13 such that the housing 13 and the outer, circumferentially extending walls 9, 9 ', 9 "touch, whereby the rigidity of the stator 4 is increased and Vibrations are damped due to radial forces. The stiffness can be further increased by the formed by the housing 13 and stator 4 Hollow chambers or incisions 15, 15 ', 15 ", for example with metal foam are filled. So that the wings 10 do not jam in the end positions, it is advantageous to form radially extending web walls in two parts, such that they have at least a first, radially extending part 20, to which the wings strike and at least one other part.

Figures 4a and 4b show a cross-section and a perspective view A third embodiment of a stator 4. Compared to that in Figure 2 illustrated embodiment, this third stator 4 is stiffer with respect to a radial force absorption. It is particularly advantageous to make the web walls such that the respective adjacent web walls 7, 7 'and the housing 13 prevent spreading under radial force (self-locking).

FIGS. 5a and 5b show a cross section and a perspective view a fourth type of stator 4. The web walls 7, 7 ', 7 "are as in formed the stator 4 retracted webs. They form with the in the circumferential direction extending walls 8, 8 ', 8 ", 9, 9', 9" of this stator 4 at the same time a part of the housing 13. Particularly advantageous in this embodiment, that through the remaining, closed annular surface, the circular outer wall 18, the housing 13 with the exception of the end wall 5 can be saved can. As a front wall 5, the sealing disc 14 (Figure 1) can be used, which is inserted on the front side of the stator 4 and the edge, for example can be crimped. From the circular outer wall 18 arise through For example, punching the web walls 7, 7 'then bent inward are. The web walls 7, 7 ', 7 "are well formed by their open ends. They can also be designed as shown in FIG. 6b and then with Sliding shoes 19 to be sealed.

Figures 6a and 6b show a perspective view of a part of a fifth and sixth stator 4, the variants of the fifth stator 4 represent. The web walls 7, 7 'are bent once inwards, the other times outwards. These stator variants 4 are therefore inserted into a housing 13. The web walls 7, 7 'are each sealed by sliding shoes 19 (FIG. 6 b). The latter support the web walls 7, 7 'and prevent deformation by external radial forces introduced.

In summary, results from the non-cutting produced components, in particular through substantial parts of the stator 4, a large mass reduction the device. A similar rigidity as in the devices of the state The technique is illustrated by the illustrated embodiments of the stator. 4 reached. At the same time, the leakage losses are reduced because of porous Sintered components or on a complex steam treatment or resin impregnation can be waived.

LIST OF REFERENCE NUMBERS

1

hydraulic device for adjusting the angle of rotation

2

camshaft

3

drive wheel

4

stator

5

bulkhead

6

rotor

7, 7 ', 7 "

web walls

8, 8 ', 8 "

outer, circumferentially extending walls

9,9 ', 9 "

inner, circumferentially extending walls

10

wing

11, 11 ', 11 "

first pressure chambers

12, 12 ', 12 "

second pressure chambers

13

outer casing

14

sealing washer

15, 15 ', 15 "

Hollow chambers or incisions

16

Element for adjustment angle limitation

17

scenery

18

circular outer wall

19

shoe

20

first, radially extending part of the web wall

21

axial central screw

Claims (18)

Internal combustion engine having a hydraulic device (1) for adjusting the rotational angle of a camshaft (2) with respect to a crankshaft, comprising: a rotor (6) with vanes (10) arranged thereon, which is non-rotatably connected to the camshaft (2), one on at least one end face provided with an end wall (5), substantially cylindrical outer contour having a stator (4) rotatably connected to a driven by the crankshaft drive wheel (3), both sides of the wing (10) pressure chambers (11, 11 ', 11 " , 12, 12 ', 12 ") are provided, in each case by web walls (7, 7', 7") and inner (9, 9 ', 9 ") and outer (8, 8', 8"), in the circumferential direction , concentrically extending walls of the stator (4) are limited and can be pressurized or emptied via a hydraulic system with hydraulic fluid, characterized in that the stator (4), in particular its web walls (7, 7 ', 7 ") and its inner and outer , in circumferential direction ung running walls (8, 8 ', 8 ", 9, 9', 9"), formed as a chipless manufactured strip or sheet metal part. Apparatus according to claim 1, characterized in that the stator (4) is reinforced at particularly stressed points locally, along the load directions by formations, beads or corresponding profiles. Apparatus according to claim 1, characterized in that the stator (4) has a preferably tubular and formed as a sheet metal part outer housing (13), the web walls (7, 7 ', 7 ") and the outer (8, 8', 8" ) and inner (9, 9 ', 9 ") walls in the circumferential direction. Apparatus according to claim 1, characterized in that the parts stator (4), housing (13) and drive wheel (3) by connection technologies of the forming technology, such as knurling, flanging, welding, caulking, riveting, gluing or bent retaining lugs are attached to each other. Apparatus according to claim 1, characterized in that the pressure chambers (11, 11 ', 11 ", 12, 12', 12") are closed at the end by an annular, designed as a sheet metal part sealing disc (14). Apparatus according to claim 5, characterized in that the sealing disc (14) with the end wall (5) is fixedly connected, which is formed integrally with the outer housing (13). Apparatus according to claim 1, characterized in that in the rotor (6) an element (16) is arranged for Verstellwinkelbegrenzung, which engages in a corresponding link (17). Apparatus according to claim 1, characterized in that the stator (4) consists of alternately outer, circumferentially extending walls (8, 8 ', 8 ") and inner, circumferentially extending walls (9, 9', 9"), respectively Are sections of a circular cylinder consists, wherein in each case adjacent outer (8, 8 ', 8 ") and inner (9, 9', 9"), circumferentially extending walls by web walls (7, 7 ', 7 ") are connected, which, together with a circular rotor (6) inserted into the stator and the vanes (10) arranged therein, form pressure chambers (11, 11 ', 11 ", 12, 12', 12") and have cavities on their sides facing away from the pressure chambers or incisions (15, 15 ', 15 ") form. Apparatus according to claim 8, characterized in that the cavities or incisions (15, 15 ', 15 ") are filled with metal foams or with plastic or injected. Apparatus according to claim 8, characterized in that the web walls (7, 7 ', 7 ") run or are formed such that the wings (10) in the end positions of the web walls (7, 7', 7") either only on strike its radially outer, only at its radially inner end or only in a central region. Apparatus according to claim 8, characterized in that the web walls (7, 7 ', 7 ") from the peripheral wall of an outer cylinder or inner cylinder are formed in pairs as retracted or withdrawn outwardly webs. Apparatus according to claim 11, characterized in that the web walls (7, 7 ', 7 ") are punched out of the inner or outer peripheral wall of the stator (4) and in pairs in the radial direction, outwardly or inwardly, are bent. Apparatus according to claim 12, characterized in that the web walls (7, 7 ', 7 ") are connected in pairs by a sliding shoe (19) supporting them and form cavities (15, 15', 15"). Apparatus according to claim 13, characterized in that the cavities (15, 15 ', 15 ") are filled by metal foams or molded or sprayed with plastic. Apparatus according to claim 8, characterized in that the web walls (7, 7 ', 7 ") form an angle of 10 ° to 30 ° to the radial, so that the wings in their end positions only the radially outer ends of the web walls (7, 7 ', 7 "). Internal combustion engine having a hydraulic device (1) for adjusting the rotational angle of a camshaft (2) with respect to a crankshaft, comprising: a rotor (6) with vanes (10) arranged thereon, which is non-rotatably connected to the camshaft (2), one on at least one end face provided with an end wall (5), substantially cylindrical outer contour having a stator (4) rotatably connected to a driven by the crankshaft drive wheel (3), both sides of the wing (10) pressure chambers (11, 11 ', 11 " , 12, 12 ', 12 ") are provided, in each case by web walls (7, 7', 7") and inner (9, 9 ', 9 ") and outer (8, 8', 8"), in the circumferential direction , concentrically extending walls of the stator (4) are limited and can be pressurized or emptied via a hydraulic system with hydraulic fluid, characterized in that the stator (4) including its web walls (7, 7 ', 7 ") and its outer (8, 8 ', 8 ") and inner (9 , 9 ', 9 "), extending in the circumferential direction walls and / or a housing comprising it (13) are formed as non-cutting produced sheet metal parts. Apparatus according to claim 16, characterized in that the pressure chambers (11, 11 ', 11 ", 12, 12', 12") are closed at the end by an annular, designed as a sheet metal part sealing disc (14). Apparatus according to claim 17, characterized in that the sealing disc (14) with the end wall (5) is fixedly connected, which is formed integrally with the housing (13).

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