Pneumatic component for a control bearing

Abstract

An active pneumatic component for pneumatically controlling a hydraulic bearing includes an electrically driven oscillating membrane pump combined with a multiway valve into an integrated structural component, in such a way that an armature which activates the oscillating membrane also controls the valve functions of the multiway valve. The valve also containing the inlet and outlet valves of the pump.

Description

[0001] The invention relates to a pneumatic component and particularly relates to an active pneumatic component.

[0002] The invention especially relates to a minimized combined component consisting of an oscillating membrane pump and a valve head having an inlet and an outlet and being switchable between different control states.

[0003] In particular, the invention relates to a pneumatic component for switching pneumatically switchable hydraulic bearings. Such bearings are well known in the field of automotive engineering.

[0004] Such a pneumatically switchable hydraulic bearing is known for example from the published German patent application DE 32 10 731 A1 disclosing a pneumatic pressure chamber defined in a cup-shaped chassis-connection fitting underneath a compensating diaphragm of a basically conventional hydraulic bearing. In the pressure chamber a variable pneumatic overpressure can be generated as a setting pressure directly influencing the stiffness of the hydraulic bearing by acting on the compensating diaphragm. According to the state of the art this pneumatic setting pressure is either externally generated and externally controlled or only externally generated and internally controlled with respect to the casing of the hydraulic bearing. This internal controlling of the pneumatic setting pressure is effected by the compensating diaphragm itself, which opens and closes a relief valve according to the deformation caused by the damping fluid located in the working chamber of the hydraulic bearing. The compensating diaphragm rolls up and down pushing a tappet of the valve to open the valve to a pneumatic pressure generator supplying constant pressure or releasing the tappet to close the valve by the restoring force of a spring. Therefore, according to the state of the art, an independent adjustment and switching of the hydraulic bearing can only be effected by a pneumatic pressure generator regulated by a real-time controller which are both located outside the component of the hydraulic bearing. This can obviously be attributed to the large size of these components which are dimensioned in accordance with the large pneumatic volumina to be moved.

[0005] According to the state of the art it is an object of the invention to provide an active pneumatic component comprising two functional components, namely pressure generation and pressure controlling that is at the same time small enough to be integrated in the casing of a conventionally dimensioned hydraulic bearing. This technical problem is solved according to the invention by a pneumatic component comprising the features of claim 1.

[0006] The dependent claims disclose embodiments of the invention.

[0007] The essential advantage which can be achieved with the component according to the invention is related to its simple and compact configuration. Due to the direct integration of the 3/2-port multiway valve in the oscillating membrane pump forming its top and accordingly due to the control of the valve operation by the pump and by means of the pump not only a miniature construction is achieved, but also not more than two lines of low voltage are required to control the switching states of the 3/2-port multiway valve as well as the states of the pump. This allows the direct integration of the pneumatic switching elements in the casing of the hydraulic bearing to be switched.

[0008] In the following, embodiments of the invention are described with respect to the unique figure of the drawings, wherein

[0009] FIG. 1 shows a pneumatic component comprising the features of the invention in an axial section.

[0010] In a casing 1 a 3/2-port multiway valve 2 and an oscillating membrane pump 3 are combined to a structural and functional unit. The multi-way valve 2 comprises an inlet 4 and an outlet 5. The inlet 4 is connected with an inlet channel 6 having an inlet valve 7.

[0011] Furthermore, the inlet 4 communicates with the outlet 5 of the component via a ventilation conduit 8 comprising a membrane valve 9 being closed by a biased spring 10.

[0012] Furthermore, the outlet 5 of the component is connected with an outlet channel 11 comprising an outlet valve 12. The outlet channel 11 is closed by the restoring force of a spring. The inlet channel 6 and the outlet channel 11 open into a pumping working chamber 13 of the oscillating membrane pump 3. On its opposite side the pumping chamber 13 is bounded by the oscillating membrane 14. The oscillating membrane 14 is driven by a plunger-type armature 15 of a reciprocating solenoid valve comprising a coil 16. The plunger-type armature 15 provides a drum-shaped cylindrical reinforcement 17 in central position of its axial extension. In a currentless or deenergized state of the magnetic coil 16 the cylindrical reinforcement 17 is supported in a defined rest position 20 by the restoring force of two restoring springs 18, 19.

[0013] When the coil 16 is energized by a constant current flow the cylinder 17 is lifted with respect to its axial center and supported in position 21 which corresponds to the maximal lifting 22 of the pumping membrane 14. In this position the membrane 14 opens the membrane valve 9 by shifting the tappet 23 extending into the pump chamber 13. The membrane valve is otherwise kept closed by the restoring force of a biased spring 10.

[0014] In case of a pulsating current flow having a rectangular pulse frequency the cylinder 17 and accordingly the armature reciprocally move back and forth. The amplitude of this oscillation is equal to the distance between the axial positions 20 and 24 with respect to the axial center of the cylinder 17. Thus the oscillating membrane 14 is lifted in the position indicated in FIG. 1 with broken lines. In this position it is just not in contact with the base 26 of the tappet 23 so that the relief valve 9 is closed. This is the normal operational state of the oscillating membrane pump 3. Furthermore a pneumatic overpressure is generated and available at the outlet fitting 5.

Claims

1. An active pneumatic component especially for pneumatically switching of a hydraulic bearing,

2. Component according to claim 1,

3. Component according to one of the claims I or 2,

4. Component according to one of the claims 1-3,

5. Component according to one of the claims 1-4,

6. Component according to one of the claims 1-5,

7. Use of the pneumatic component comprising features of one or more of the claims 1-6 for pneumatically switching of hydraulic bearings in motor vehicles, said bearings comprising a loose piece for uncoupling vibrations and a control chamber having a displaceable wall which is formed by the loose piece.