摘要:
The invention relates to an acceleration measuring device (1) comprising a piezoelectric system (2), a seismic mass (3), and a base plate (4); during an acceleration, the seismic mass (3) applies a force, which is proportionate to the acceleration thereof, to the piezoelectric system (2), said force generates piezoelectric charges in the piezoelectric system (2), and said piezoelectric charges can be electrically picked up as acceleration signals; the seismic mass (3) includes two mass elements (30, 30'); positive piezoelectric charges can be electrically picked up as acceleration signals on a first mass element (30), and negative piezoelectric charges can be electrically picked up as acceleration signals on a second mass element (30').
摘要:
The invention relates to a piezoelectric sensor consisting of a base support (2), a piezoelectric measuring sensor arranged on said base support (2), a protective layer (3) covering the measuring sensor and an electronic evaluation system (4). The measuring sensor (1) is formed from a piezoelectric layer (1), the base support (2) has a first contact layer (5) which is electrically connected to the piezoelectric layer (1) and the protective layer (3) comprises a second contact layer (6) which is electrically connected to the piezoelectric layer (1). The electronic evaluation system (4) can determine a mechanical charge of the piezoelectric layer (1) by evaluating the difference of the electric potential between the first contact layer (5) and the second contact layer (6).
摘要:
The invention concerns a knock sensor (1) comprising a base (10) consisting of a flange (12) and a cylindrical sleeve (11) threaded at the end opposite to the flange, a stack (20) sensitive to accelerations comprising at least a piezoelectric element (22), threaded on the sleeve, and a nut (30) co-operating with the sleeve thread (13) to prestress the stack between the flange and the nut. The invention is characterised in that the locking interface (20a) between the nut and the stack is made of materials with friction coefficient adapted to limit the prestress load (F) applied to the stack.
摘要:
The proposal is for a device for measuring acceleration via piezoelectric transducers. The device has a prior art bearer (14, 16) with a parallel main shaft for acceleration measurement, a seismic mass (20, 22) held so as to move in relation to the bearer and piezoelectric units (12, 12') acting in pairs and connected so as to be excited, in which the arrangement is such that pyroelectric effects are compensated. According to the invention, the bearer has a cross-member (16) extending transversely to the main shaft and the piezoelectric units excited by compression are fitted thereon on its opposite sides in relation to the direction of the main shaft between the latter and the seismic mass (20, 22). This results in temperature-independence and insensitivity to ground expansion and acceleration of any other kind and direction than linear and parallel to the main shaft.
摘要:
Die Erfindung bezieht sich auf ein Überwachungssystem für Grossanlagen, z.B. von Diesel- oder Gasmotoren sowie von Kolbenkompressoren und allgemein zyklisch arbeitenden Maschinen in Schiffen, Plattformen, Kraftwerken, Fabriken etc. Das erfindungsgemässe Überwachungssystem umfasst Sensoren (1, 6), die sowohl die Zylinderkraft, die Kolbenstellung als auch hochfrequente Motoren- oder Maschinengeräusche erfassen und mittels eines Computersystems analysieren. Entsprechende Signal-auf-bereitungs- und Kalibrieranlagen sowie problemspezifische Computer-Software ergänzen das Monitoring-System, das jeweils den Anforderungen der Kunden angepasst wird. Von Bedeutung ist, dass die Sensoren (1, 6) ohne mechanische Änderungen an der zu überwachenden Maschine montiert und auch jederzeit demontiert werden können. Die Anlage eignet sich somit für die Erstausrüstung wie auch die Nachrüstung. Erfindungsgemäss besteht der Sensor für die beiden Messgrössen Zylinderkraft und Körperschall aus einer Einheit; auch zwei Einheiten sind möglich. Wichtig im Sinne der Erfindung ist, dass beide Messgrössen simultan zur Überwachung der Anlage eingesetzt und deren Signale laufend analysiert werden. Vorzugsweise ist der Sensor als Dünnscheibensensor (1) ausgebildet, der mit einer normalen Unterlagscheibe der Zylinderkopfschraube auswechselbar ist.
摘要:
This invention relates to an impact sensor which does not have any electric contacts exposed to the open air and any moving portions but has high durability and high reliability and can reliably detect collision of a car for a long period even when mounted on a car. The impact sensor comprises a piezoelectric element (3, 13) which, when compressed, generate a voltage corresponding to the compressive force, a pair of electrode (1c, 1d, 11c, 14) sandwiching the piezoelectric element, an inertia member (6, 16) for applying the compressive force to one of the electrodes and a biasing member (7, 17) for biasing the inertia member (6, 16) towards the piezoelectric element (3, 13). When an impact force is applied to the inertia member (6,16), the inertia member (6, 16) compresses the piezoelectric element (3,13) with the compressive force corresponding to this impact force and the piezoelectric element (3, 13) generates the voltage corresponding to the compressive force.
摘要:
L'accéléromètre (1) comprend, d'une part, un corps (2) destiné à être fixé sur une pièce dont les accélérations ou les vibrations sont à détecter, d'autre part un élément piézo-électrique (8) précontraint entre ce corps (2) et une masse sismique (9) , et d'autre part enfin des moyens de liaison électrique souples (E) entre deux faces opposées (15, 16) de l'élément piézo-électrique et des bornes d'un connecteur (19) monté sur le corps d'accéléromètre, des moyens d'isolation électrique étant en outre prévus entre les faces (15, 16) de l'élément piézo-électrique et les parties voisines de l'accéléromètre. Le connecteur (19) est monté sur le corps (2) d'accéléromètre à l'aide de moyens d'amortissement (D) propres à réduire ou à supprimer la transmission mécanique des vibrations ou accélérations du corps d'accéléromètre au connecteur.