RU2412448C2 - Shock proof vibration transducer of angular speed - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: proposed transducer comprises case, sensitive element excitation circuit and data signal processing circuit. Sensitive element is arranged on flexible suspensions and is made up of triangular-section metal bar with piezoelectric plates fitted on bar end faces. Flexible suspensions are made up of two rings. Three spring elements are arranged inside said rings, there are cutouts on bar ribs to fix said spring elements therein. Sensitive element with flexible suspension is placed in capsule consisting of sleeve and two support assemblies with protective elements to protect against lengthwise and transverse shocks. Said protective elements comprises two thrusts arranged on the bar lengthwise axis and six thrusts arranged perpendicular to bar lateral faces in symmetry about it crosswise axis to adjust the clearance relative to bar faces. Note here that sad thrusts are made from soft metal, e.g. lead.

EFFECT: higher sock resistance.

3 dwg

Description

The invention relates to small-sized vibration sensors for angular velocity (TLS). In particular, it concerns vibrating TLS, which have high impact resistance and are used in motion control systems for objects subject to shocks up to 10000 g.

Known vibrational DOS (patent EP 0664439 B1), the sensitive element of which is made of metal material in the form of a beam with a triangular section, to one of the ribs of which are attached U-shaped elastic suspensions.

In this solution, the elastic suspensions are also electric current leads to the common electrodes of the piezoelectric plates mounted on the edges of the beam.

The disadvantage of this solution is the lack of strength of the sensing element with U-shaped suspensions.

The closest technical solution to the invention is patent US 5505085 A.

In this invention, the elastic suspensions for the beam sensing element are U-shaped elastic frames that can be attached to one of the ribs or to one of the faces.

The disadvantage of the prototype is the insecurity of the sensitive element and the TLS as a whole from the effects of longitudinal and transverse impacts.

The problem to which the present invention is directed, is to achieve a technical result, which consists in increasing the impact resistance of the CRS.

The indicated technical result is achieved in that the impact-resistant vibrational DOS contains a housing, an electrical circuit for exciting the sensing element and processing information signals, a sensitive element in the form of a beam of triangular cross section made of metal material with piezoelectric plates on the faces, mounted on elastic suspensions, and the elastic suspensions are made in the form of two rings, inside of which three spring elements are formed, slots are made on the edges of the beam, in which the spring element is attached s of elastic suspensions, a sensitive element with elastic suspensions is placed in a capsule consisting of a sleeve, in the end recesses of which the aforementioned elastic suspensions are fixed, and two supporting units with elements for protecting the sensitive element from longitudinal and transverse impacts, containing two beams located on the longitudinal axis along both its side of the stop with the ability to adjust the amount of clearance relative to the ends of the beam and six stops installed perpendicular to the side faces of the beam, symmetrically about its transverse axis, also with the possibility of adjusting the size of the gap relative to the edges of the beam, and the stops are made of soft metal, for example, lead.

Thus, the distinguishing features of the invention is that the elastic suspensions are made in the form of two rings, inside of which three spring elements are formed, slots are made on the edges of the beam, in which the spring elements of the elastic suspensions are attached, a sensitive element with elastic suspensions is placed in a capsule consisting from a sleeve, in the end recesses of which the aforementioned elastic suspensions are fixed, and two supporting units with elements for protecting the sensitive element from longitudinal and transverse impacts, containing two data on the longitudinal axis of the beam on both sides of the stop with the possibility of adjusting the gap relative to the ends of the beam and six stops installed perpendicular to the side faces of the beam, symmetrically about its transverse axis, also with the ability to adjust the size of the gap relative to the edges of the beam, and the stops are made of soft metal for example from lead.

The specified set of distinctive features of the design allows to achieve a technical result, which consists in increasing the impact resistance of the sensing element and the TLS as a whole.

The invention is illustrated by figures 1, 2, 3.

Figure 1 shows a General view of the beam sensor assembly with elastic suspensions in the capsule.

Figure 2 - elastic suspension with a fixed beam.

Figure 3 is a cross section of a support node with security elements.

An example implementation of the proposed CRS

A sensitive element 1 (Fig. 1) of a TLS in the form of a beam with a cross section of a regular triangle and elastic suspensions 2 (Fig. 2) are made of elinvar alloy, which is characterized by stability of elastic properties and a low coefficient of linear expansion. Elastic suspensions are mounted on the beam sensitive element in the places of its vibration nodes in such a way that the spring elements 3 of the suspensions are latched into the slots 4, made on the edges of the beam strictly in the zero plane of its vibrations on the first bending mode. This achieves a high durability of the connection of the suspensions 2 with the beam 1, which is one of the conditions for high impact resistance of the TLS. The spring elements 3 of the elastic suspensions 2 are fixed in the slots 4 of the beam by soldering. The external contour of the ring suspensions 2 are fixed in the end recesses 5 (figure 1) of the sleeve 6 also by soldering. The sleeve contains two guide pins 7 - one for each support node 8 and three contact pads 9 isolated from the sleeve for outputting the current leads 10 from the piezoelectric elements 11. The support node 8 contains protective elements of the sensitive element - stops 12, 13 (Figs. 1, 3) from longitudinal and transverse impacts, respectively, and has a slot 14 (Fig. 1) for the guide pin 7 of the sleeve. The stops 12 are located at the ends of the support nodes 8, and the stops 13 are located on the side of the support nodes 8 through 120 ° opposite the three faces of the beam 1. The stops 12, 13 are lead screws with small threads. The current leads are made of a platinum-silver tape with a cross section of 20 μm × 200 μm with a specific electrical resistance of 0.3 · 10 ^-6 Ohm / m and a tensile strength of 2 GPa. A high tensile strength determines the stability of current leads in the conditions of assembly and operation, including during overloads up to 10000 g. The current leads to the common electrodes of the piezoelectric plates are the aforementioned ring suspensions. The support nodes to the sleeve are attached by glue.

The main condition for the operation of the TLS after impact is to preserve the deformations of suspensions 2 within the elastic range, including after an impact of 10,000 g in any direction. Calculations and experiments established that this condition is satisfied if the gap δ between the stops 12, 13 and the corresponding faces of the beam 1 is in the range of 20 μm - 30 μm.

The gap value δ is adjusted with respect to the edges of the beam when a sensitive element is included in the excitation circuit. Observing the harmonic excitation signal from the sensing element on the oscilloscope, slowly turn all eight stops in turn until the harmonic signal disappears on the oscilloscope. This means that the stop touched the beam and damped its vibrations. To ensure a gap of δ≈20 μm, it is necessary to unscrew the stop with a thread pitch of 0.75 mm, turning it by ≈10 °. In this case, the beam oscillations will resume, and the harmonic signal appears again on the oscilloscope.

After adjusting the clearance, the positions of the stops 12, 13 are fixed with glue.

The test results of the created impact-resistant vibrational beam CRS with a sensitive element 30 mm long and the described construction confirmed its resistance to impact along three axes 10000g with a duration of 0.5 ms.

Claims (1)

An impact-resistant vibration angular velocity sensor, comprising a housing, an electric circuit for exciting the sensing element and processing information signals, a sensing element in the form of a beam of triangular cross section made of metal material with piezoelectric plates on the faces, mounted on elastic suspensions, characterized in that the elastic suspensions are made in the form of two rings , inside of which three spring elements are formed, slots are made on the edges of the beam, in which spring elements of elastic suspensions are attached s, a sensitive element with elastic suspensions is placed in a capsule consisting of a sleeve, in the end recesses of which the aforementioned elastic suspensions are fixed, and two supporting units with elements for protecting the sensitive element from longitudinal and transverse impacts, containing two beams located on its longitudinal axis on both sides emphasis with the ability to adjust the amount of clearance relative to the ends of the beam and six stops mounted perpendicular to the side faces of the beam, symmetrically about its transverse axis, also with the possibility Adjusting the size of the gap relative to the beam edges, the stops are made of soft metal such as lead.

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