RU2054616C1 - Method of making sealed strain sensitive resistors - Google Patents

Abstract

FIELD: measuring technique. SUBSTANCE: method of making sealed strain sensitive resistors (tensoresistors) comprises steps of manufacturing a protective casing, having a cavity for strain sensitive resistor and a through opening, in which a horizontal pipe is arranged by fluid-tight fashion for outlet of connecting leads; joining the casing by roller contact welding with a substrate of a steel belt, supporting the strain sensitive resistor; before welding placing a removable insert of an electrically conductive material on the leading out pipe, filling a gap between the pipe and the substrate; performing a welding seam along the whole perimeter of the casing; removing the insert. EFFECT: enhanced structure of the resistor for strain testing in heavy conditions. 1 cl, 4 dwg

Description

 The invention relates to manufacturing technology in a protective housing of strain gages susceptible to water, aggressive media, gas flow, as well as external pressure, and can be used for tensometric testing of structural elements in these operating conditions.

Known methods for the manufacture of strain gages for use in various environments [1]
A known method of manufacturing a sealed strain gauge, including the manufacture of a protective housing with a cavity under the strain gauge and a through hole in which a horizontal tube is installed for the output of communication lines, is sealed and a weld is made when the housing is connected to a substrate of steel tape on which the strain gauge is mounted using a contact roller welding [2]
This technical solution is the closest to the invention in technical essence and the achieved result. However, this method provides for special additional technological operations and structural elements for the implementation of the output of the tube with communication lines from the sensor housing and fastening the tube to the substrate, which complicates the method and reduces the productivity of the manufacturing process.

 In FIG. 1 shows the relative position of the elements of the sealed strain gauge before welding; in FIG. 2 the same, in the process of contact roller welding during the passage of the weld, under a horizontal tube, side view; in FIG. 3 the same after welding; in FIG. 4 conductive insert.

 The manufacture of a sealed strain gage is carried out in the following technological sequence. A strain gauge 2 with communication lines 3 is mounted on a substrate 1 of steel tape. A protective case 4 is made with a cavity under the strain gauge 2 and a through hole 5, in which a horizontal tube 6 is sealed for output of the communication lines 3 of the strain gauge 2. Hermetic connection of the protective case 4 with the substrate 1 is carried out by contact roller welding.

 To perform a weld along the entire perimeter of the housing 4, including under the horizontal tube 6, insert (install) an insert 7 of electrically conductive material that fills the gap between the tube 6 and the substrate 1. The weld 8 is made using rollers 9 .

 After welding, the liner 7 is removed. As a result of this operation, the sealed strain gauge is ready for operation. To the object 10, the substrate 1 of the strain gauge is attached by spot welding 11.

 Thus, in comparison with the prototype, a simplification of the manufacturing method and an increase in its productivity are achieved due to the fact that in the manufacture of a sealed strain gauge in a protective case, it is possible to seal a seam under a horizontal tube without additional technological operations, using only contact welding carried out by a single technological launch, and also it is not required to introduce special structural elements and technological operations for horizontal fastening th tube to the substrate.

 Implementation of the claimed proposal.

Produced by the inventive process batch sealed sensor based on high-grade tenzotermorezistorov TTP PM-22-23 (24) with a base 10x7 mm field 20. Temperature 550 ^C (50 copies) on the basis of strain gages and KF-mark 5 for normal temperature with base 10x2 , 2 mm (60 copies) and with a base of 5 x 2.8 mm. Sensor housings are made of tape art. 12X18H10T 0.3 mm thick, tubes for outputting communication lines from st. 12X18H10T, diameter 3 x 0.5 mm. The output tube was connected to the housing by soldering.

 The overall dimensions of the sensors are given in the table.

 Each sensor instance was subjected to a leak test in a water medium under an external pressure of 2 MPa. The shape stability of the shell (body) is maintained up to a pressure of (7.8) MPa.

 Metrological certification of batches of sealed strain gages with the definition of a standard set of standardized characteristics in accordance with GOST 21615-76 was carried out. The sensitivity of sealed strain gages is (7.12)% lower than that of the corresponding strain gages in the usual version.

 The compensation temperature of the TCS strain gages in a sealed design is fully preserved.

Claims (1)

 METHOD FOR PRODUCING SEALED TENSOR RESISTORS, which consists in the fact that they produce a protective case with a cavity for the strain gauge and a through hole for hermetically installing the tube for the output conductors, fix the strain gauge to the substrate from a steel tape and connect the protective case to the substrate by contact roller welding, which differs by before welding, an insert of electrically conductive material is installed on the tube in the gap between the tube and the substrate, a weld is made along the entire perimeter of housing, including the place above the tube with the liner, after which the liner is removed.

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