BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is directed to an adjustable damping valve device having a coil carrier with a magnetic coil wound on an inner sleeve and a back iron having a passage for a power supply line of the magnetic coil placed on the coil carrier.

2. Background of the Invention

FIGS. 2 to 11of DE 10 2009 059 808 A1, the entire content of which is incorporated herein by reference, describe details of a coil housing and of the back iron cooperating therewith. As is shown in particular inFIGS. 4 to 7, a coil housing has an inner sleeve on which the coil is wound. The two wire ends of the wound coil penetrate an upper edge of the coil housing and run radially inward through a connection bridge to a cable connection. The connection bridge forms a raised yoke which is received by a back iron which is placed on an upper side of the coil housing. There is no bonding connection between the back iron and the coil housing, for example, via a potting compound. Instead, the back iron has a groove which extends along the entire center axis. The groove divides the back iron into two identical circle segments which are held together by a cover. The inside of the cover forms a groove base in relation to the groove.

In the endeavor to minimize the constructional length of an adjustable damping valve device, special consideration must be accorded to the coil housing because a comparatively large installation space must be made available for it. It is thus an object of the present invention to optimize the constructional length of an adjustable damping valve device.

SUMMARY OF THE INVENTION

This object is met in that the wire ends of the coil are co-located adjacent to one another in an outlet area of the coil carrier, and the back iron has a radial slot which extends from the outer edge of the back iron to the passage and has a width which corresponds at least to the width of the outlet area.

The advantage consists in that the installation space for the yoke used heretofore is no longer needed. Consequently, the headroom for the cover area at the back iron is also dispensed with. The C-shape of the back iron can be produced simply. In theory, the C-shape of the back iron leads to a worsening of the magnetic flux of the coil. However, it has been shown that there is no noticeable loss in lift force as a result of the axial distance between the magnetic field area at the transition between the back iron and coil and a valve armature which is to be moved.

The back iron is advantageously constructed as a planar disk which can be produced simply and with sufficient precision, for example, in a sintering process or stamping process.

The damping valve device can be kept particularly variable when the back iron is constructed as a stack of laminations.

According to an advantageous embodiment, the coil carrier has a toroidal support surface for the back iron. With the toroidal support surface, an armature guide can engage in the installation space bounded by the toroidal support surface so that a compact constructional form can be achieved.

Further, it is provided that the coil carrier has a centering profile for the back iron. An eccentricity of the back iron relative to the coil carrier for the armature guide can be minimized via the centering profile. The constructional unit comprising back iron and coil carrier is inserted into a valve housing which serves as conductor for the magnetic flux. As a result of the centering, jamming can be prevented (joining for interference fit is ensured in this way in particular) and a uniform magnetic flux transition can be achieved.

The back iron can basically be mounted as an appended part because the coil carrier is fixed together with the back iron inside of the valve housing. Therefore, fixing would not be absolutely necessary. For the assembly phase in which the back iron is connected to the coil carrier but is not yet fixed in the valve housing, it can be provided that the back iron has at least two locating holes in direction of the coil, the coil carrier being fabricated from a plastic and a retaining connection to the locating holes being closed during the process of producing the coil carrier. The constructional unit comprising back iron and coil carrier can be handled easily without the parts coming loose from one another.

In a further advantageous configuration, the coil carrier has a guide for the power supply line extending from the toroidal support surface as a radially extending land. The guide facilitates the contact between the wound coil and the power supply line. The guide has a width which can be inserted into the radial slot of the back iron.

According to a further advantageous embodiment, the inner sleeve of the coil carrier has a centering profile for an armature guide inside the inner sleeve. An air gap between the inner sleeve and the armature guide is bridged via the centering profile.

For the purpose of a simple assembly, the guide has an axial end stop for the power supply line.

For a very simple construction of the coil carrier, the centering profile for the back iron is formed at the guide for the power supply line. The centering profile may be formed by simple projecting lands.

In order that all of the relevant structural component parts for the functioning of the damping valve device are optimally positioned relative to one another, the centering profile for the back iron and the centering profile for the armature guide have an identical basic shape and an identical angular orientation.

Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.

