RU217110U1 - Impact start sensor - Google Patents

Abstract

The utility model relates to measuring equipment used mainly in testing ammunition, in particular contact fuses. The impact start moment sensor contains a housing with a piezoceramic element installed in it and leads connected to the metallized surfaces of the piezoelectric element. To operate under high shock loads, a piezoceramic element for fuses made of lead zirconate-titanate TsTS-19 was used as a piezoceramic element, made with the possibility of loading upon impact along the polarization axis. The sensor is provided with a shock-absorbing pad installed between the piezoceramic element and the housing, which is affected by the impact, and the test equipment assembly is used as the housing. The proposed sensor can be installed both in the striker when testing the ammunition by throwing, and in the anvil of the copra when testing on the copra. The technical result of the utility model is the creation of a reliable and simple sensor for measuring the start moment of a large impact. 2 ill.

Description

FIELD OF TECHNOLOGY

The utility model relates to measuring equipment used mainly in testing ammunition, in particular contact fuses.

To measure the time parameters of contact fuses, in most cases it is necessary to fix the moment of the start of the impact (meeting with the target). Tests of contact fuses are carried out with imitation of real shock effects on impact impact testers of the Masset type (Publisher FGBOU VPO "MSTU named after N.E. Bauman". El No. FS 77 - 48211. ISSN 1994-0408 77-30569 / 322339 Features of playing shock impacts during mechanical tests # 02, February 2012 authors: Efremov A.K., Kapustyan A.V. (UDC 620.178.)

Known sensors for the start of an impact of an electromagnetic type with various schemes for the device of a movable body and contacts (for example, USSR author's certificate No. ), piezoelectric sensors - commercially available accelerometers and sensors with a special shape of the piezoelectric element (for example, patent RU No. 2684139 C1 dated September 15, 2013, patent RU No. 2533539 C1 dated May 27, 2013, patent RU No. 2621467 C1 dated 06/30/2016) . Possessing high sensitivity, like known piezo sensors, or low shock resistance, like electromagnetic sensors, and sufficient technological complexity, they are not very suitable for operation under high shock loads. The disadvantages of the known piezoelectric sensors is a large range of side vibrations that require the use of additional processing to isolate the main signal, and electromagnetic sensors are destroyed by large impacts or require the use of protection, which greatly complicates the design.

The closest analogue can be considered a shock sensor according to patent RU No. 2621467 C1.

The task to be solved by the claimed technical solution is to create a more reliable and structurally simple device for determining the moment of impact at high shock loads (impact force of the order of tens of thousands of N, acceleration of thousands of ms ^-2 ).

This problem is solved due to the fact that a piezoceramic element for fuses according to GOST B 16437-86 made of TsTS-19 material of cylindrical shape is used as a measuring element of the signal sensor. test equipment that transmits a shock to the product, while to reduce interference, the sensor housing is enclosed in shock-absorbing material, and the signal to the load (meter) is fed through a diode. This solution ensures the resistance of the sensor to large impacts, because. the force limit during compression of the piezoelectric element is at least 23600 N. When hitting the target, the impact force of the ammunition reaches 50000-100000 N. At the same time, a charge is created with a compression force of 5000N

Q=d ₃₃ ⋅F= ^270⋅10-12 Kl/H⋅5000H= ^135⋅10-8 Kl,

which provides at the input load capacitance C=1000⋅10 ^-12 F output signal

U=Q/C=135⋅10 ^-8 C/1000⋅10 ^-12 F=1350 V,

where d ₃₃ - piezoelectric element in static mode, C/N;

Q - charge, C;

F - impact force, N;

C - input capacitance, F;

U - signal voltage, V.

Depreciation reduces the compression force until the sensor receives the voltage value of 50-100 V necessary for indicating, at which interference is removed almost to zero, both from the sensor and from external pickups.

The technical result of the utility model is the creation of a reliable and simple sensor for measuring the start moment of a large impact. The proposed sensor can be installed both in the striker when testing the ammunition by throwing, and in the anvil of the copra when testing on the copra. In this case, a unit of test equipment (the impactor body or the copra anvil itself) can be used as the sensor body.

DISCLOSURE OF UTILITY MODEL

The utility model is illustrated by a description and an example of practical use, in which the sensor is made from parts of a serial fuse piezoelectric generator (patent RU No. 205478 dated 03.03.2021).

The essence of the utility model is illustrated by drawings (Fig. 1, Fig. 2), where in Fig. 1 shows a general view of the sensor, Fig. 2 shows its installation with a shock absorber in the body. The shape and dimensions of the housing are selected based on the location of its installation or the test equipment assembly used.

The sensor (Fig. 1) consists of a housing 6, a lower contact 5 isolated from the housing with plastic 4, a piezoelectric element 3 made of lead zirconate-titanate, a steel striker 2, a clamping nut 1, a lobe 7 fixed with a nut 8, and leads 9 connected to petal 7 and bottom contact 5.

The installation of the sensor (Fig. 2) in the body 11, which perceives the impact, is carried out through the shock-absorbing pad 10.

The design of the sensor does not cause difficulties in its manufacture.

IMPLEMENTATION OF UTILITY MODEL

The sensor works as follows.

When hitting the impactor of the test bench, the piezoelectric element 3 is compressed between the lower contact 5 and the impactor 2, resulting in a potential difference on the electrodes of the piezoelectric element 3, which is fed through the leads 9 to the measurement circuit. Lead wires 9 are output from node 11 in a convenient location depending on the design of the test bench. The shock absorber 10, for example, rubber, is selected empirically to obtain the necessary parameters - the magnitude of the signal and interference. To fix only the first voltage pulse, a diode is placed in the measurement circuit, and a discharge resistance can be connected in parallel with the meter input to provide the necessary discharge time for the meter input capacitance.

Tests of the sensor during the control of serial fuses at the throwing stand showed good results in terms of performance and stability, its use was introduced into the test procedure approved by the general customer.

Claims (1)

Impact start moment sensor, containing a body with a piezoceramic element installed in it, and leads connected to the metallized surfaces of the piezoelectric element, characterized in that for operation at high impact loads, a piezoceramic element for fuses made of lead zirconate-titanate TsTS-19 is used as a piezoceramic element , made with the possibility of loading upon impact along the polarization axis, and the sensor is equipped with a shock-absorbing gasket installed between the piezoceramic element and the body, which is affected by the impact, and the test equipment assembly is used as the body.

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