| 摘要 |
FIELD: linear transducers furnished with a counting mechanism, can be used in various branches of industry, in particular, for monitoring the service life of building structures, bridges, cranes, motor vehicles, aircraft, etc. SUBSTANCE: the service life counter has a casing intended for attachment to the construction member, disk installed in the casing for turning relative to its axis, support intended for attachment to the construction member, and a pusher installed for reciprocating motion in the plane of disk turning; one end of the pusher is placed in the support and the other is engageable with the disk; to enhance the sensitivity, a rocker is rigidly attached to the end of the pusher located in the casing, the rocker ends through dogs are linked with double-arm levers, one of which is the disk, and the other - the lever installed on the axle of the disk, it terminates in a ratchet-and-pawl gear; the length of the lever arm from the axis of rotation to the dogs- A, and the length from the axis of rotation to the point of contact of the ratchet-and-pawl gear with the ratchet wheels - B are selected from ratio A/B≅1,; ratchet wheels with ratchet wheel revolution counters are installed on the disk in circumference at definite intervals, they come in engagement with the ratchet-and-pawl gear. The sealed casing has a hole for visual inspection of the counters; each ratchet wheel has an electrical contact, and another electrical contact is installed on the lever with the ratchet-and-pawl gear; for the end position of the lever with the ratchet-and-pawl gear an electrical contact of the construction emergency state is installed. Provision of two double-arm levers makes it possible to enhance the transducer sensitivity by 2B/A times, and due to the fact that the pusher is made of the same material as the construction under test, and the disk with the double-arm lever is made of material with the minimum thermal coefficient of expansion, it becomes possible to almost completely prevent the temperature errors of measurement. Installation of strain level gauges makes it possible to obtain an integral repeatability of peak values of the construction strain at any time moment up to the complete expiration of service life. Mechanical variant of the transducer with a sealed casing and hole for visual inspection of the counters makes it fully independent, and there is no need in constant technical control and maintenance in service. EFFECT: enhanced sensitivity and minimum temperature errors. 2 cl, 1 dwg |
