Patent Application
20190376421
This disclosure relates to a camshaft adjustment device for changing the angular position of a camshaft relative to a crankshaft of an internal combustion engine, said device comprising an actuator.
The disclosure is in the field of proportional magnets used as electromagnetic actuating devices for actuating hydraulic directional control valves. An electromagnetic actuating device is used as a central magnet for controlling a hydraulic camshaft adjuster of an internal combustion engine, for example. The disclosure can be employed with electromechanical camshaft adjusters for internal combustion engines. In this case, an actuator designed as an electric motor is provided for the adjustment of the adjusting shaft. Such electric motors generally comprise a stator unit having a sensor function, a rotor subassembly, and a housing unit.
DE 10 2012 003 648 B3 discloses a proportionately acting electromagnet having a plastic overmolding with an integrally molded fastening flange. The fastening flange includes molded elements, which, in interaction with molded elements on the housing, allow mounting of the electromagnet on and partially in the housing by pressing in axially and twisting. The molded elements hold the electromagnet on and partially in the housing axially and against twisting by means of a latching action, which hinders the rotary motion. Springs consisting of sheet metal perform both the axial preloading for the mounting of the electromagnet and the spring latching for maintaining the rotational position. The preloading forces of the springs for mounting the electromagnet and for latching during the rotation of the electromagnet are produced during assembly by integrally molded bevels on the molded elements. The configuration of the seal which seals off the radial gap between the electromagnet and the housing ensures that it is matched to a low axial assembly force.
DE 10 2011 080 265 A1 furthermore discloses an electric motor having a housing unit, wherein the electric motor is configured as an actuating motor of a camshaft adjuster for an internal combustion engine. The housing unit has an integrally molded plastic flange and a deep drawn housing at least partially surrounded by said plastics material.
DE 10 2016 221 990 A1 shows an electromagnetic actuating device having a housing flange that has a latching contour. The actuating device is fastened with the aid of a latching clip, which has two legs and a connecting section. A latching section is formed on each of the legs. The latching section interacts in such a way with a latching contour of the component accommodating the electromagnetic actuating device that permanent fastening of the electromagnetic actuating device on the component accommodating the actuating device is made possible. The latching contour on the receiving component is embodied as a groove into which the latching clip engages by means of its latching section, which is embodied as a recess facing the opposite leg. With the aid of the recess in each leg, a positive joint is established between the actuating device and the receiving component.
DE 10 2013 114 625 A1 shows another embodiment of an electromagnetic actuating device. A description is given of an electromagnetic actuator having a fastening means for fixing the actuator on an engine element. The fastening means have positive engagement means as an anti-rotation means, which are designed and arranged in such a way that the actuator can be adjusted toward the engine element, into an assembly position, by a purely translational assembly movement. To secure it, leaf springs are pushed into an opening, wherein the opening is formed by a housing flange and a mating contour of a component which accommodates the actuator.
The problem addressed by the present disclosure is that of providing a camshaft adjustment device, comprising an actuator having a housing flange and comprising a housing which accommodates the housing flange, which features improved assembly.
The solution to this problem results from the features, advantageous developments and embodiments of the disclosure that are described herein.
A camshaft adjustment device, according to the disclosure, for changing the angular position of a camshaft relative to a crankshaft of an internal combustion engine, comprises an actuator for actuating a hydraulic valve. The actuator has a housing flange, and a fastening means is provided to retain the housing flange on a housing. A latching section is formed on the housing, and a retaining section, which comes to bear axially on the latching section, is formed on the housing flange. The fastening means comprises at least two fastening clips for connecting the housing to the housing flange in a positive and a nonpositive manner. Each fastening clip has a first leg with a first latching contour and a second leg with a second latching contour. The first latching contour of the first leg alone is provided to come to bear against a latching groove in the latching section, and the second latching contour of the second leg alone is provided to come to bear against a latching groove in the retaining section.
The camshaft adjustment device can be of electromechanical design and can have an actuator designed as an electric motor. It is likewise also possible for the camshaft adjustment device to be of electromagnetic design and to have an actuator designed as a proportional magnet, which is provided for the actuation of hydraulic directional control valves.
The actuator of the camshaft adjustment device, in particular the housing flange of the actuator, is mounted on the housing, in particular on a cover of a chain case. In principle, however, it is also possible for the housing accommodating the actuator to be the actual cover of a timing mechanism, e.g. the cover of a chain drive. The housing flange can be produced from a metallic material, but a component produced from a plastic or component overmolded with plastic is also conceivable. The housing and the latching section formed on the housing can be produced from a metallic material.
The retention of the housing flange on the housing is accomplished by the fastening means when the housing flange bears axially against the housing. To fix the housing flange axially on the housing, the at least two fastening clips are connected, on the one hand, to the latching section and, on the other hand, to the retaining section. A fastening clip should be taken to mean a clamp which connects two elements positively and nonpositively. The fastening clips can be formed from a metallic material, in particular a spring steel, or from a flexible plastic. The respective fastening clips can advantageously be pushed radially onto the latching section of the housing in order to fix the housing and the housing flange at least axially.
The first latching contour and the second latching contour of each fastening clip can be connected to one another by a connecting leg. In particular, the connecting leg is of arc-shaped design. The arc-shaped design of the connecting leg advantageously results in a spring action of the fastening clip as the housing flange is locked to the housing, thus ensuring a positive and nonpositive joint. Consequently, the fastening clip is under a preload in a locked state, thereby preventing play and relative movement between the housing flange and the housing.
According to an illustrative embodiment, two buckle contours are formed on the second leg of each fastening clip, wherein a respective pin element formed on the retaining section passes through each buckle contour, wherein the respective pin elements are provided for the purpose of receiving each fastening clip with play on the housing flange. In other words, the second leg of the fastening clip is mounted with play on the housing flange. In the locked state, the first leg of the fastening clip is connected positively and nonpositively to the housing, and the second leg of the fastening clip is connected positively and nonpositively to the housing flange.
The two buckle contours of each fastening clip have a respective opening, wherein the opening can be of square or rectangular design. As an alternative, a circular opening is also conceivable. The respective pin elements formed on the retaining section pass through the opening in each buckle contour, wherein the cross section of each pin element is smaller than the cross section of the opening in each buckle contour. The term “pass through” should be taken to mean that each pin element is passed through the opening in the respective buckle contour. In other words, the pin element is accommodated in a freely movable manner in the respective buckle contour.
As a further embodiment, the first leg of each fastening clip has an assembly tab for locking the housing flange to the housing. The fastening clip can pivot in a locking direction about a fulcrum by virtue of an actuation of the assembly tab, wherein the first latching contour latches into the latching groove in the latching section. The assembly tab is actuated by a pressing action in the axial direction of the housing. A fulcrum is taken to mean the contact point between the latching contour and the latching groove of the housing flange, about which the fastening clip is pivoted during the actuation of the assembly tab. Through the entry of the latching contour into the latching groove of the latching section, the fastening clip is fixed, and the housing flange is thus connected to the housing. In the locked state, the geometrical design of the fastening clip ensures simultaneous reception of the first latching contour in the latching groove of the latching section and of the second latching contour in the latching groove of the retaining section.
The second leg of each fastening clip can have a disassembly tab for unlocking the housing flange from the housing. It is advantageous if the disassembly tab is formed at an acute angle to the surface of the housing flange in the locked state, wherein each fastening clip pivots in an unlocking direction about the fulcrum by virtue of an actuation of the disassembly tab. At a distal end section of the disassembly tab, a pressure point is provided, at which the disassembly tab is actuated with a pressing action, wherein a lever arm is formed between the pressure point and the fulcrum. The angle of the disassembly tab relative to the surface of the housing flange and the length of the lever arm are provided for rapid and simple disassembly of the actuator.
As a further embodiment, the housing flange has an orientation contour for the alignment of the actuator on the housing. The orientation contour can interact positively with a housing contour formed in a manner substantially complementary thereto and, in particular, is used to position the at least two fastening clips on the housing.
Further measures that improve the disclosure are illustrated in greater detail below, together with the description of an illustrative embodiment of the disclosure, by means of the four figures, wherein identical or similar elements are provided with the same reference characters. In the drawings:
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| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2017 104 981.9 | Mar 2017 | DE | national |
This application is the U.S. National Phase of PCT Application No. PCT/DE2018/100209 filed on Mar. 8, 2018 which claims priority to DE 10 2017 104 981.9 filed on Mar. 9, 2017, the entire disclosures of which are incorporated by reference herein.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/DE2018/100209 | 3/8/2018 | WO | 00 |
