RU2537614C2 - Method and device for cellular filler stretching - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: invention relates to construction, ship building, aircraft and aerospace engineering, particularly, to cellular filler stretching. Proposed method allows the making of spatial structure of cellular filler geometrically similar in three mutually perpendicular directions. Note here that stretching is performed in steps at continuous measurement of stretching force at the rate varying inversely with cellular package web tension up to intermediate stops at forces approximating to critical value for given type of cellular filler. Motion is resumed after said force is decreased to permissible value after redistribution over the entire length of cellular web. Proposed device allows stretching of different-size cellular packages.

EFFECT: higher quality, decreased quantity of rejects.

2 cl, 2 dwg

Description

The invention relates to various fields of industry, primarily construction, shipbuilding, aviation, space and rocket. In particular, the invention relates to methods and devices for manufacturing a honeycomb core (SZ) for honeycomb structures.

Cellular aggregate is a structural element of a three-layer honeycomb structure. It is made of aluminum foil of grades AMg2-N, 5052, 5056 with a thickness of 20 ÷ 23 microns. The shape of the cell is a 2.5–5 mm hexagon. The honeycomb core in a three-layer honeycomb structure in which two covering sheets of aluminum alloys or carbon fiber are firmly glued to the aluminum filler placed between them - honeycomb - takes up mechanical loads and protects the thin supporting layers from local and general loss of stability, while ensuring their teamwork and high rigidity.

Despite the expanded scope of three-layer honeycomb structures, SZ itself, as a structural material, is the most poorly studied structural element.

To significantly increase the strength and stiffness of honeycomb structures, SZ should have a regular spatial structure composed of plates, which, as a rule, is geometrically similar in three mutually perpendicular directions.

In the state of supply, the SZ comes in the form of honeycomb packets (in unstretched form). Honeycomb packets are processed (cut) to the desired size in unstretched condition. Stretching honeycomb packers is carried out on special equipment. The main problem here is local gaps and uneven stretching of the honeycomb, especially with large sizes of honeycomb core. The authors are not aware of sources of information describing methods and devices for stretching a honeycomb core.

The value of the honeycomb package strength during delamination is indicated in the passport for the supplied honeycomb packages (see Appendix 1). In general, the delamination strength according to TU 14311577.237-02 (see Appendix 2) “Cellular glued core from aluminum foil” should be at least 0.7 kG / cm (see Appendix 3). This effort applies to all types of cellular aggregates in question.

The force required to stretch the package in this way depends on the geometric dimensions of the honeycomb. For a honeycomb packet of known sizes, the critical value of the tensile force is calculated.

The aim of the invention is to improve the quality of the product.

This goal is achieved due to the fact that when stretching the honeycomb core, honeycomb packages are fixed on one side fixedly to the connecting element of the honeycomb extension device, on the other hand they are mounted on a movable carriage mounted through force sensors in linear modules connected by a common shaft; set the critical tensile force from the control panel of the control system, turn on the servo drive and start the movement of the carriage; continuously measure the tensile force of the honeycomb package on the force sensors, inversely proportional to the force, change the speed of the carriage; when the critical force value is reached for a given stretch size of a given movement of the carriage, stop and resume after the tensile force becomes less critical due to the expansion of the honeycomb cells.

A device for stretching a honeycomb core comprises linear modules connected to a common shaft and connecting elements to which a movable carriage is attached via force sensors; honeycomb mounting elements located on a carriage and connecting elements; a servo driving a common shaft; a system for controlling the speed of movement of a common carriage.

The invention is illustrated in the drawing, which shows the device in two projections.

The device for stretching the honeycomb packet 1 consists of a table 2, two typical linear modules 3. The device uses linear belt modules. They are a belt drive with a gear belt and linear ball guides, enclosed in an aluminum profile housing. The carriage of the linear module 3, mounted on linear bearings, is driven by a belt attached to it from the inside. Belt pulleys are mounted in ball bearing housings. Linear modules 3 are combined for synchronous movement of the common carriage 4 with a common shaft 5 and are fastened at the edges by two connecting elements 6. The common shaft 5 is driven by a servo drive 7. In addition, the device includes an electrical cabinet 8 and a control system (not shown in the drawing).

The connecting elements 6 and the common carriage 4 are made of aluminum profiles with grooves in which the fasteners for the honeycomb package 1 are installed - hooks 9. The common carriage 4, in turn, is attached to the carriages of the linear modules 3 through two weight cells - force sensors 10.

The control system based on the microcontroller allows you to control the servo 7 - to regulate the speed of movement of the carriage 4 depending on the readings of the force sensors 10.

The method of stretching consists in the fact that in order to obtain the spatial structure of the honeycomb core, geometrically similar in three mutually perpendicular directions, it is proposed to perform the stretching operation in stages at a rate that varies inversely with the tension of the honeycomb web, up to intermediate stops upon reaching a force value equal to critical for this type of honeycomb, and resume movement after this effort, due to redistribution along the entire length of popolotnoy, will become lower than the critical value for this type of honeycomb core, while the tensile force is measured continuously.

Stretching the honeycomb core is as follows. Honeycomb pack 1 is installed on table 2, fixed on hooks 9 on one side to a fixed connecting element 6, and on the other to a movable carriage 4. The operator sets the critical tensile force values for this type of honeycomb packet from the control panel and includes a servo drive 7. Common carriage 4 starts the movement by stretching the honeycomb packet 1. As the tensile force on the weight cells 10 increases, and inversely proportional to the value of this force, the control system reduces the speed of the carriage 4. If, nevertheless, the value of the tensile force value becomes equal to the critical value specified by the operator, the servo drive 7 stops the stretching. The force is redistributed along the entire length of the honeycomb packet 1, the cells expand, the force on the weight cells 10 decreases and the movement of the carriage 4 resumes. A similar algorithm allows you to stretch honeycomb packets of any size within the geometric dimensions of the installation, without specifying the final coordinate of stretching. In practice, it has been established that if, after the next stretching cycle, the force does not decrease within 30-40 s, this means that the stretching is completed, the control system turns off the servo drive 7 and sends a signal to the operator about the completion of the process.

The implementation of this solution allows you to create three-layer honeycomb structures, including large sizes, in which a honeycomb made of one honeycomb pack is installed, which allows to increase the mechanical strength and rigidity of the structure as a whole, nullify the marriage when stretching honeycomb packets by automating the process and due to the elimination of the human factor.

Claims (2)

1. The method of stretching the honeycomb core, which consists in the fact that on the one hand the honeycomb package is fixed motionless on the connecting element of the device for stretching the honeycomb core, on the other hand is fixed on a movable carriage mounted through force sensors in linear modules connected by a common shaft; set the critical tensile force for a given type of honeycomb filler from the control panel of the control system, turn on the servo drive and start the carriage movement; continuously measure the tensile force of the honeycomb package on the force sensors, inversely proportional to the force, change the speed of the carriage; upon reaching the value of the tensile force of a predetermined critical tensile value for a given type of honeycomb core, the carriage stops and resumes after the tensile force becomes less than critical for this type of honeycomb core. 2. A device for stretching a honeycomb core for implementing the method according to claim 1, comprising linear modules connected to a common shaft and connecting elements to which a movable carriage is attached via force sensors; honeycomb mounting elements located on a carriage and connecting elements; a servo driving a common shaft; a system for controlling the speed of movement of a common carriage.

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