FR2554876A1 - COMPOSITE MATERIAL BASED CYLINDER - Google Patents

Abstract

THE SUBJECT OF THE INVENTION IS A CYLINDER OF THE TYPE INCLUDING A BODY IN WHICH A SOLIDARITY PISTON SLIDES A ROD SLIDING THROUGH ONE OF THE HEADS OF THE CYLINDER, CHARACTERIZED IN THAT THE BODY 7 OF THE CYLINDER AND THE ROD 15 OF THE CYLINDER INCLUDE COMPOSITE MATERIALS CONSTITUTED OF A CROSS-LINKED POLYMER MATRIX AND REINFORCING FIBERS AND IN THAT THE HEADS OF THE CYLINDER 10, 11 HAVE THE FORM OF A TERMINAL COVERING THE ENDS OF THE BODY 7 OF THE CYLINDER AND ARE FIXED TO THIS BODY 7 BY GLUING .

Description

1. The present invention relates to a cylinder based on

composite materials.

  Until now, the cylinders are completely made of metal. However, for certain applications, these jacks prove to be too heavy. We therefore looked for cylinders of lower weight, these cylinders being able to withstand pressures as high as

completely metal cylinders.

  The present invention aims to provide such materials.

  rins. It relates to a cylinder of the type comprising a cylindrical body in which slides a piston secured to a rod sliding through one of the heads of the cylinder, characterized

  in that the cylinder body and the cylinder rod comprise

  nent composite materials consisting of a crosslinked polymer matrix and reinforcing fibers, and in that the cylinder heads have the shape of a nozzle covering the ends of the cylinder body and are fixed to this body

by collage.

  The composite materials that are used in the

  present invention are materials called "high per-

  formances ", characterized by high mechanical resistance

  vee, both in flexion and in compression.

  They include a crosslinked polymer matrix which

  is obtained by crosslinking a thermosetting resin.

  These thermosetting resins used can

  be in particular epoxy resins and poly-

  imides. Reinforcement fibers are fibers with "high

  performance ", such as glass or carbon fibers.

  The cylinder body advantageously consists of one or more windings of fiber filaments of

  reinforcement embedded in a crosslinked polymer matrix.

  This cylinder body can be obtained by winding filaments impregnated with thermosetting resin on a 2. mandrel covered with a non-stick product, hardening of the resin (for example by heating) and removal of the

mandrel after hardening.

  To improve the mechanical resistance, the cylinder body can also include a tubular metal core.

  thin lique. The cylinder body is then produced by

  rolling of filaments impregnated with thermosetting resin

  sand on a thin metal tube which remains in place after crosslinking of the resin and constitutes the core of the

cylinder body.

  This embodiment also makes it possible to reduce or eliminate the precise machining of the bore of the body of the

  cylinder, depending on the accuracy class of the chosen body.

  The cylinder rod can be produced by molding a mixture of thermosetting resin and fibers

  reinforcement in a thin metal tube. After reticu-

  lation of the resin a hybrid rod is obtained comprising

  a thin metal casing. This rod is particularly

  Rather light and has good mechanical properties.

  As with the metallic core of the cylinder body, this

  metal velvet reduces or eliminates machining, depending on

  the accuracy class of the chosen tube.

  You can also obtain the cylinder rod by

molding the mixture in a mold.

  After crosslinking, the mold is removed and

  obtains a particularly light and efficient rod.

  Alternatively, the stems can be obtained by pulp

  continuous trusion in a thermoregulated machine provided with a die through which the mixture is extruded and is crosslinked. The stems are then cut with the

desired length.

  The cylinder heads can be metallic, plastic or composite material. These heads, which have a fluid inlet or outlet have the shape of a nozzle and come to cap the ends of the

cylinder body.

  3. The cylinder heads are glued to the body by

  a thermosetting adhesive, in particular an epoxy adhesive.

  The cylinder rods are also glued to the pegs

  tones, conventionally made of metal, and at their other end to the control member. The cylinders according to the present invention are thus much easier to assemble than the metal cylinders

  "bitube" type classics where crimping was necessary

  to be. These cylinders have pressure withstand up to 25.106 Pa and even 50.106 Pa, in the case of

body with a metallic soul.

  These cylinders also have weights of at least

  50% less than that of conventional metal cylinders.

  These cylinders have, moreover, a very good resistance to shocks, in particular to the impact of small projectiles,

  whereas conventional metal cylinders are subjected to ai-

  definitely a permanent deformation. This good impact resistance makes it possible to maintain the operation of these jacks, even in the event of an accidental impact, which is very important from the point of view of safety (in particular in the automobile industry, the armaments industries, aeronautics). The invention is set out below in more detail at

  using drawings representing only modes of exe

  cution. In these drawings: FIG. 1 is a cross-sectional view of a jack body used in the invention; Fig. 2 is a variant of FIG. 1; Fig. 3 is a cross-sectional view of a jack rod used in the invention; Fig. 4 is a variant of FIG. 3; Fig. 5 is a view in longitudinal section of a

  cylinder according to the present invention.

  The cylinder body shown schematically in FIG. 1 is constituted by a cylindrical winding 1 4. of filaments of fibers such as glass fibers,

  coated in a matrix 2 of thermosetting resin.

  The cylinder body shown in FIG. 2 is a variant of FIG. 1. The body further comprises a thin metallic tubular core 3.

  The cylinder rod shown in FIG. 3 is cons-

  with a matrix 4 of cylindrical shape containing

  the dispersed state of the reinforcing fibers 5.

  The cylinder rod shown in FIG. 4 is a variant of FIG. 3 and includes a metal casing

thin 6.

  The cylinder according to the invention shown in Fig.5 comprises a cylindrical body of composite material. His

  two ends 8 and 9 are topped with respective end caps

  10 and 11 which are glued to the ends 8 and 9.

  The nozzles 10 and 11 are provided with resistor pipes

  pectively 12 and 13, supply and outlet of hydraulic fluid. The end piece 11 is provided with a bore 14 through which slides the rod 15 of the jack which is also made of composite material. At the end of this rod 15 is

glued a metal piston 16.

  The following examples illustrate the manufacture of

cylinders according to the invention.

EXAMPLE 1

a) Cylinder body

  The cylinder body consists of a tube

  posite realized by filament winding of fibers

  E glass impregnated with epoxy resin consisting of a

  lange of 100 parts by weight of diglycidyl ether of Bis-phenol A having an epoxy equivalent of 195 and a viscosity of 19 Pa.s at 25 C and 11 parts by weight of triethyltetramine, on a mandrel having a diameter of 28

  mm and coated with a non-stick product.

  The composite structure consists of the layers

  following ches: 5. A glass veil A layer at 90 A layer at - 54 A layer at 90 A layer at + 54 A layer at 90 After winding, the assembly is placed 1 h 30 at

   C. Then we proceed to the mandandering.

  b) Cylinder rod The cylinder rod consists of E glass fibers impregnated with epoxy resin (Percentage fibers /

resin: 75/25).

  The composite rod is molded by pultrusion of E glass fibers, impregnated with epoxy resin through

a die heated to 140 C.

  The running speed is 1 m / min.

  The stem length is cut continuously. The metal ends are then bonded (piston and control member) using a

  epoxy adhesive (treatment for 1 hour at 130 C).

c) Assembly

  The assembly of light alloy cylinder heads

  This is done by gluing with an epoxy adhesive (treatment

  lie for 1 hour. at 130 C). We obtain a resistant cylinder

at a pressure of 25.10 Pa.

  The total weight of composite materials and cylinder heads is only 363 g, a gain

  by weight of about 60% compared to a metal jack.

EXAMPLE 2

  The cylinder body consists of a winding of R glass fibers impregnated with epoxy resin.

  with a mixture of 100 parts by weight of diglyci ether

  Bis-phenol A dylic acid having an epoxide equivalent of and a viscosity of 13.5 Pa.s at 25 C and 38 parts by weight of 4,4'-methylene dianiline on a thin metal tube made of XC 48, thickness 3 / 10 and an inside diameter

28 mm.

  6. The winding of the glass fibers R impregnated on the metal tube is carried out so as to result in the following hydride composite structure: Steel tube 3/10 A layer at 90 A layer at 45 A layer at 90 After winding, the assembly is placed in an oven

for 2 h. at 80 C.

  The rod and the piston are similar to those used.

read in Example 1.

  The cylinder heads are made up of two parts

made of Z 200 C13 steel.

  The assembly of the body and the heads is done by gluing with an epoxy adhesive (treatment for 1 h.

at 130 C).

  This produces a pressure-resistant cylinder

from 35.106 Pa.

  The total weight of composite materials and cylinder heads represents only 371 g, a gain

  about 60% compared to a conventional metal cylinder.

7.

Claims (4)

  1. Cylinder of the type comprising a cylindrical body   in which slides a piston secured to a rod   smoothing through one of the heads of the jack, characterized in that the body (7) of the jack and the rod (15) of the jack comprise composite materials consisting of a   cross-linked polymer matrix (2,4) and reinforcing fibers   cement (1,5) and in that the heads of the jack (10,11) have the shape of a nozzle covering the ends of the body (7)   of the jack and are fixed to this body (7) by gluing.   2. Jack according to claim 1, characterized in that the body (7) of the jack consists of one or   several windings (1) of filaments of reinforcement fibers   necessarily embedded in a crosslinked polymer matrix (2).   3. Cylinder according to claim 1 or the res-   dication 2, characterized in that the cylinder body comprises   also takes a thin metallic tubular core (3).   4. Cylinder according to any one of the claims   1 to 3, characterized in that the cylinder rod has   also takes a thin metal casing (6).