Vibration pickup with pressure sheath

Details Vibration pickup with pressure sheath Vibration pickup with pressure sheath

1999-12-21

2001-08-28

Kwok, Helen (Department: 2856)

Measuring and testing

Engine detonation

Specific type of detonation sensor

C073S654000

Reexamination Certificate

active

06279381

ABSTRACT:

BACKGROUND OF THE INVENTION
The invention is directed to a vibration pickup or vibration transducer with a pressure sleeve.
A vibration transducer with a pressure sleeve used as a knock sensor for monitoring the operation of an internal combustion engine in a motor vehicle has already been described in DE-OS 44 03 660. This pressure sleeve is fixedly joined to the structural component part causing the vibrations, in this case, the engine block, via a support area. The vibrations to be detected are knocking noises of the operating internal combustion engine which are conducted via the pressure sleeve to a piezoceramic disk serving as the actual sensor element and accordingly converted into an electric output signal capable of evaluation.
The manner in which this sensor element is arranged on and clamped to the pressure sleeve and the fastening of the pressure sleeve to the vibrating structural component part have a great influence on the method of manufacture. The clamping of the sensor element, including a plurality of individual parts, e.g., a spring and a seismic mass, is carried out in this known vibration transducer by relatively elaborate production steps.
In accordance with the present invention, in a vibration transducer with a pressure sleeve, a seismic mass is provided with an internal thread and is screwable directly to the pressure sleeve for clamping a sensor element of the transducer.
SUMMARY OF THE INVENTION
The vibration transducer, is advantageous in particular in that a separate plate spring for generating axial pretensioning can be dispensed with when joining the individual parts for clamping the sensor element. Since the contact disks which contact the axial surfaces of the piezoceramic sensor element in order to produce electrical contact are already formed in the manner of a plate spring, there is no longer any need for separately producing and mounting a plate spring.
The contact disks can be stamped out from a sheet metal part in a simple manner in such a way that a radially extending curvature or an inclination or slope of the contact disks brings about the springing effect. When stamping out, a connector for connecting a connection cable to the contact disk can also advantageously be provided at the same time, so that this connector is integral with the respective contact disk from the start and a costly assembly step for the electrical connection of these parts can therefore be dispensed with.
The vibration transducer according to the invention can accordingly be produced in a few assembly steps with a reduced number of parts, so that there is no need for special tools for arranging a plate spring or for separate soldered or welded contact connectors. This not only saves on manufacturing costs and manufacturing time, but also increases the reliability of manufacture through the simplified construction.
In another advantageous embodiment form, a separate threaded ring or other fastening means by which the seismic mass is clamped in can also be dispensed with. In this case, the seismic mass itself is outfitted with an internal thread and, if necessary, with an external hexagon, so that the clamping can be carried out automatically. Accordingly, it is possible to further reduce the parts number, the manufacturing time and the weight while maintaining a high manufacturing quality and manufacturing reliability.


REFERENCES:
patent: 5398540 (1995-03-01), Entenmann et al.
patent: 5872307 (1999-02-01), Brammer et al.
patent: 5939616 (1999-08-01), Ito et al.
patent: 40 11 910 A (1991-10-01), None
patent: 44 03 660 A1 (1994-10-01), None
patent: 196 12 540 A (1997-01-01), None
Patent Abstracts of Japan vol. 009, No. 016 (P-329), Jan. 23, 1985 & JP 59 164921 A, Sep. 18, 1984.

Affiliated with

Also associated with

Rating

Vibration pickup with pressure sheath does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Vibration pickup with pressure sheath, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Vibration pickup with pressure sheath will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2473772