Carbon-basalt hybrid composite stud

Abstract

This utility model relates to stud-type fastener designs and can be used for assembling threaded connections in mechanical engineering, particularly for the manufacture of highly loaded connections made of composite materials. The technical result of this utility model is to increase the stability of the threaded and face connection of studs by improving the rigidity of epoxy hybrid composites.A composite carbon-basalt hybrid stud comprising a threaded portion up to the shoulder and a threaded portion at the opposite end of the stud, a shoulder for abutment, a hexagon and a cylindrical portion, wherein the stud is made of a composite material including a basalt base in the form of roving fiber impregnated with a binding epoxy resin, the hexagon is formed by a stamp from a heated blank, wherein the basalt base in the form of roving fiber impregnated with a binding epoxy resin is made with the addition of carbon fiber crumbs of various diameters and silicon carbide powder, preliminarily uniformly mixed in the resin, wherein the length of the carbon fiber crumb cylinders is equal to the difference between the outer diameter of the stud thread and its inner diameter. 2 ill.

Description

[0001] Technical field

[0002] The utility model relates to the design of stud-type fasteners and can be used for assembling threaded connections in mechanical engineering, in particular for the manufacture of highly loaded connections made of composite materials.

[0003] Technology Level

[0004] A device is known for a stud made of a composite basalt material (patent RU 219140 IPC F16B 35 / 04. Published: 06 / 30 / 2023 Bulletin No. 19), containing a threaded portion up to the flange and a threaded portion at the opposite end of the stud, a flange for stopping, a hexagon and a cylindrical portion, wherein the stud is made of a composite material including a basalt base in the form of a fiber impregnated with binding resins, the hexagon is formed by a stamp from a heated blank, and the basalt base in the form of a fiber impregnated with binding resins is made with the addition of basalt powder, previously uniformly mixed in the resin.

[0005] The disadvantage of the known device is the low stability of the threaded connection of the stud.

[0006] The closest known device is a stud made of composite basalt material (patent RU 223994 IPC B29D 1 / 00, F16B 35 / 04. Published: 03 / 12 / 2024 Bulletin No. 8), containing a threaded portion to the shoulder and a threaded portion at the opposite end of the stud, a shoulder for stopping, a hexagon and a cylindrical portion, wherein the stud is made of a composite material including a basalt base in the form of a fiber impregnated with binding resins, the hexagon is formed by a stamp from a heated blank, and the basalt base in the form of a fiber impregnated with binding resins is made with the addition of basalt fiber chips, pre-mixed uniformly in the resin, and the length of the cylinders of basalt fiber chips is equal to the difference between the outer diameter of the stud thread and its inner diameter.

[0007] The disadvantage of the closest device is the low stability of the threaded connection of the stud.

[0008] Disclosure of Utility Model

[0009] The technical result of the utility model is to increase the stability of the threaded and edge connection of the stud by improving the rigidity of epoxy hybrid composites.

[0010] The present technical result is achieved in a composite carbon-basalt hybrid stud device, comprising a threaded portion up to a flange and a threaded portion at the opposite end of the stud, a flange for support, a hexagon and a cylindrical portion, wherein the stud is made of a composite material including a basalt base in the form of roving fiber impregnated with a binding epoxy resin, the hexagon is formed by a stamp from a heated blank, wherein the basalt base in the form of roving fiber impregnated with a binding epoxy resin is made with the addition of carbon fiber crumbs with different diameters and silicon carbide powder, preliminarily uniformly mixed in the resin, wherein the length of the carbon fiber crumbs cylinders is equal to the difference between the outer diameter of the stud thread and its inner diameter.

[0011] Distinctive features are

[0012] basalt base in the form of roving fiber impregnated with epoxy resin binder, made with the addition of carbon fiber crumbs with different diameters and silicon carbide powder, the use of such material increases the stability of the threaded connection by improving the rigidity of epoxy hybrid composites, by combining carbon fiber with different diameters, randomly uniformly located in the roving body, and silicon carbide powder material [3];

[0013] Preliminary uniform mixing of carbon fiber with silicon carbide powder in the binder resin, this maintains the stability of the threaded and edge connection due to the rigidity of hybrid epoxy composites [4];

[0014] The length of the carbon fiber crumb cylinders is equal to the difference between the outer diameter of the stud thread and its inner diameter, which increases the stability of the stud threaded connection by improving the rigidity of epoxy composites.

[0015] A comparison of the claimed solution with analogs and the prototype did not reveal any features that distinguish the claimed solution, which allows us to conclude that it meets the “novelty” criterion.

[0016] Brief description of figures

[0017] Fig. 1 shows a front view of a composite hybrid basalt-carbon stud impregnated with a binder resin with the addition of carbon fiber crumbs and silicon carbide powder, including: 1 - a threaded portion up to the flange; 2 - a flange for abutment; 3 - a cylindrical portion; 4 - a hexagon, 5 - a threaded portion at the opposite end of the stud.

[0018] Fig. 2 shows cutout A along the thread of the stud from Fig. 1, including: 1 - stud thread; 6 - basalt towing threads arranged in the required order; 7 - silicon carbide powder; 8 - cylinders of carbon fiber, the length of which is equal to the difference between the outer diameter of the stud thread and its inner diameter; 9 - basalt towing threads deformed by the knurling tool.

[0019] Implementation of a utility model

[0020] The main raw material for the production of basalt studs is basalt roving. In addition, the following is required to manufacture composite studs: resins; ethyl alcohol; acetone; dicyandiamide. Carbon fiber cylindrical crumbs, obtained from carbon fiber threads by chopping the roving into a bundle in a chopping machine [5], in two stages with different thread diameters. The length of the crumb cylinders 8 depends on the feed rate of the fiber roving and the lowering speed of the knife. Silicon carbide powder is obtained from carbon fiber waste from the carbon industry by grinding it in an AGO-2S planetary ball mill and sifting the fraction to 35-38 µm.

[0021] The basalt stud production technology is as follows. 6 roving threads are fed from a special creel device to a tensioning mechanism, where they are arranged in the appropriate order. Once arranged in the specified order, the 6 threads undergo a drying and hot-air preheating stage. The heated roving is immersed in an impregnation bath containing resin, previously uniformly mixed in a mixer with 8 carbon fiber crumbs and 7 silicon carbide powder. The continuous composite rod is passed through a drawing mechanism, at the exit of which the rod is cut to the specified size. After the impregnation bath, the material is drawn through a die to produce the stud body, a cylindrical part 3, with a specified cross-sectional area and length, taking into account the formation of a hexagon 4 using a stamp from a heated blank at a distance below the thread.The profiling die can be made, for example, in the form of a split steel structure consisting of two rectangles with a milled and processed groove half-figure along the length of each part, which, when closed, form a surface in the form of a circle corresponding to the cross-sectional area of ​​the target device.

[0022] A three-station automatic press is used for the production of composite studs. Hot stamping of hexagon 4 is performed in three process stages. At the first stamping position, the blank is calibrated and the formation of hexagon 4 begins. Beginning with the second stamping position, the internal hexagon 4 with its ribs and faces is formed. At the third stamping position, the formation of the shank calibration for flange 2 in the stud blank is completed. For knurling, the shank is formed according to the average diameter of threads 1 and 5. The knurling tool has a taper with the same profile when viewed from the end and with the full thread height. Thread 1 is formed by knurling from both ends of the stud, with the basalt threads 9 deformed during the threading process.Randomly, half the length of the 8 carbon fiber crumb cylinders remains in the body of the stud, and the other half is formed in its thread 1 or 5, equal to the difference between the outer diameter of the stud thread and its inner diameter.

[0023] The prepared stud is sent to a tunnel oven, designed to accelerate the polymerization of the impregnating resin. The hot stud is then sent to a chilled bath, where it is completely cooled under running water. The cooled stud is calibrated on an automatic lathe for threads 1 and 5 and shoulder stop 2.

[0024] The average uniaxial compression strength of basalt is 650 MPa [6], the average strength of carbon fiber crumbs in the form of cylinders with different diameters and silicon carbide powder is 2400 MPa [7], this increases the surface stability of the device made of carbon fiber with different diameters and silicon carbide powder

[0025] The claimed device, a composite carbon-basalt hybrid stud, increases the stability of the threaded and edge connection of the key during its operation and eliminates the possibility of their weakening.

[0026] Sources of information

[0027] 1. Patent RU 219140 MPK F16B 35 / 04. Published: 06 / 30 / 2023 Bulletin. No. 19.

[0028] 2. Patent RU 223994 MPK B29D 1 / 00, F16B 35 / 04. Published: 03 / 12 / 2024 Bulletin. No. 8.

[0029] 3. Hybrid influence of basalt fibers and basalt powder on thermomechanical properties of epoxy composites. Composites Part B: Mechanical Engineering, Vol. 125, 2017, pp. 157-164.

[0030] 4. Gavrilov M.A. Technology of production and chemical-biological stability of epoxy composites based on production waste. Diss. Cand. Tech. Sciences, p. 278 pp. 128,133-134. http: / / dissovet.pguas.ru / files / 212-184-01 / Gavrilov / Dissertaciya_GavrilovMA.pdf.

[0031] 5. Fiberglass chopping machine. https: / / oborudovanie.myprom.ru / product / rubochnaya-gilotina-dlya-vseh-tipov-volokon_95420.

[0032] 6. Fundamentals of Rock Physics, Geomechanics, and Massif State Management. Portsevskiy A.K., Katkov G.A. UMO approval (No. 51-73 of June 28, 2004). Registered with the Federal Education Agency (No. 5374 of November 16, 2005). - 120 p. - p. 21.

[0033] 7. Grishina O.I., Serpova V.M. Influence of silicon carbide fiber diameter on the mechanical properties of composite materials. Composite materials. Proceedings of VIAM No. 5 (65) 2018, p. 57.

Claims

A composite carbon-basalt hybrid stud, comprising a threaded portion up to the shoulder and a threaded portion at the opposite end of the stud, a shoulder for support, a hexagon and a cylindrical portion, wherein the stud is made of a composite material including a basalt base in the form of roving fiber impregnated with a binding epoxy resin, the hexagon being formed by a stamp from a heated blank, characterized in that the basalt base in the form of roving fiber impregnated with a binding epoxy resin is made with the addition of carbon fiber crumbs of various diameters and silicon carbide powder, previously uniformly mixed in the resin, wherein the length of the carbon fiber crumbs cylinders is equal to the difference between the outer diameter of the stud thread and its inner diameter.

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