FR2541605A1 - PROCESS FOR THE PRODUCTION OF SPHERICAL HEAD TOURILLONS - Google Patents

Abstract

A.PROCESS FOR THE MANUFACTURE OF SPHERICAL HEAD TRUNNELS; B. PROCESS CHARACTERIZED IN THAT, AT LEAST IN THE LAST STEP OF THE PRESSING OF CREEP, A CLOSED PRESSING BOX 1 IS USED FOR THE FORMING OF THE SPHERE 6 AND THEN THE EXTERNAL SURFACE OF THE SPHERE 6 SO OBTAINED IS USED TO ITS IMPOSED DIMENSION AND DEGREE OF POLISHING DESIRED BY A ROLLER ROLLING OPERATION. C. THE INVENTION RELATES TO A PROCESS FOR MANUFACTURING SPHERICAL HEAD JOURNALS.

Description

1 i - "Process for the manufacture of spherical trunnions"

  The invention relates to a method for the manufacture of rods and journals with a ball head

  taking a rod and a sphere arranged on one end

  of this stem, starting from a basic sketch-

  cylindrical section with a massive cross-section, on the

  which the spherical head is formed by pressing of

  ge, preferably at several stages, using a

  chon or pressing box and pressing punch

creep of the metal.

  Trunnions or spherical axes are

  used, for example, for

  It is necessary, in this case, that

  the spherical head retains extremely

  and, as a result, has an outer surface

  very low roughness Starting from an essen-

  In a substantially cylindrical, solid cross-sectional manner, the sphere has been pre-formed by a multistage creep pressing operation in a passage sleeve or an open housing. open pressing, a raw sphere was obtained which had, in its median area, a circular protruding edge or burr In a subsequent work operation, this rib was eliminated In another working operation, the sphere 2.- was brought , by machining with chip removal, at its

  imposed dimension, and finally, in a final

  ration of work, the outer sarface was polished at

medium of smooth rollers.

  DE-21 07 459 discloses a method for the manufacture of hollow steel spheres serving as nodes elements in partitioned structures in

  this case, we proceed by first forming a matrix

  this two half-shells each having a shape-like edge

  nusoldale, after which these half-shells are assembled

  with their converging edges and are then welded

  they are along their circular separation joint.

  In another way, the hollow spheres are forged in one piece in a matrix, in which case a hollow cylinder is first cast as a blank, this cylinder being previously formed with conical ends,

  after which the hollow semi-product thus obtained is

  formed in a matrix in its spherical final form

  matrix consists of two halves, which, in the final state,

  forming parts, form a closed matrix, which

  results from the application of the halves one on the other.

  As a result, in all cases, the shape of a sphere

  The hollow can only be imperfect.

  For these known steel hollow spheres,

  which serve as node elements for partition structures.

  these are building parts to which

  a requirement of precision is not imposed for their size.

  They are comparable only approximately to

  precision mechanical parts, such as

  the represented by a spherical ball pin used

  as a steering bar in an automobile.

  For a mass-produced article of

  high quality, the measures mentioned above constitute

  kill a very expensive forming process.

  The purpose of this invention is to simplify the forming process.

  for such spherical trunnions, while allowing

  with this simplified process, the production of an article

high quality key.

  In accordance with the invention, this object is

  dyed with a process characterized in that, at least in the last creep pressing step for forming the sphere, a closed pressing box is used, and then the outer surface of the sphere thus obtained is fed to its imposed dimension and is made smooth by "roller rolling" Through the claimed process, the manufacture

  is extraordinarily simplified and made less costly

  In addition, by the work operation, provided subsequently, of the outer surface (by rolling with rollers), one

  obtain a higher quality product than those achieved

  until today It is obvious to the man of art

  that the known process for producing hollow spheres

  its steel elements as elements of structural knots

  is not a prior art for the characteristics

  of the present invention.

  The invention is explained hereinafter using

  of an exemplary embodiment with reference to the drawings

  in which: FIG. 1 is a perspective view of a cylindrical blank piece with solid solid cross-section,

  FIG. 2 is a longitudinal sectional view

  of the creep press forming mold in the last step of the process applied to date,

  FIG. 3 is a longitudinal sectional view

  dinale of the pressing mold according to the invention,

  FIG. 4 is a diagrammatic representation

  of a rolling roller forming device, Figure 5 shows the trunnion

spherical finished.

4.-

  From a cylindrical blank to dry

  solid cross-section, as shown in FIG. 1, it is formed, at first, at one end,

  a sphere, by a pressing-creep process in particular

  ifer steps, the last step is shown in longitudinal section in Figure 2 The pressing box 1 used here, consists of two parts 2 and 3 and is used in the open state, that is to say, during the action of the pressing punch 4, the two parts 2 and 3 of the press housing 1 are spaced from each other, so that 2 under the action of the punch, the material of the workpiece draft can flow into the

  slot 5 between the two parts 2 and 3 of the

  Thus, on the sphere 6 to form a burr 7 shaped circular rib The pressing box is, in this case, dimensioned so that the sphere 6 obtained by forming and has a median rib 7 , being oversized compared to

  imposed dimension In a work operation

  However, this rib 7 is eliminated and the sphere 6 is machined by removal of material, to its imposed size. The outer surface of the sphere is then polished by roller rolling and the pin 8 of the pin is made by machining with removal of material. cylinder material

draft.

  In accordance with the proposal of

  tion, it is used a creep forming casing material 1 'which is closed and consists of two parts

  2 'and 3' This box is then dimensioned in such a way

  re that it presents the imposed dimension of the sphere 6 'to be made with an excess of dimension corresponding to

  the diameter reduction caused by the rolling operation

  Later pebble age The external surface roughness

  re of the previously formed sphere 6 'then corresponds

  at an extra thickness of about 6 to 12 microns.

5.-

  The two parts 2 'and 3' form the bot-

  In a part 21, is assembled cou-

  smoothing the press punch 4 'In the case of the process according to the invention, the two parts 2', 3 'constituting the pressing box 1' which receive the blank part

  possibly pre-formed having a trans-

  firstly, the press punch 4 'is actuated to act directly on the material of the blank constituting the sphere 6 during this action of the punch,

  the two parts 2 'and 3' of the pressing mold are connected with

  strung directly and seamlessly with each other for

  form the closed pressing box.

  Then the sphere 6 'is rounded by

  peel until the surface roughness cor-

  is less than 3 microns thick.

  the rolling operation, on the one hand, the quality of the outer surface of the sphere 6 'is improved, and,

  on the other hand the sphere is brought to its precise dimension.

  The trunnion rod is then formed,

  the usual way, by machining with chip removal.

  However, it could also be brought to its shape

  definitive by roller rolling The spherical head

  completed is shown in Figure 5.

  FIG. 4 schematically represents a roller rolling device. It comprises a shaft

  hammer carrier on which are slidably mounted

  The pressure rollers 14 are freely rotatably mounted in a roll cage 15 which is itself surrounded by an outer ring of brass 16. 'a rotation of the hammer shaft 10, the slides 12 and the t utes of hammers 13 are

  pushed radially outwards by the centrifugal force

  fug the hammerheads 13 thus move below 6, -

  The individual pressure rollers 140

  each receive its pressure pulse inwards

  which is transmitted as a conformational force on the

  12 and thus on the workpiece, not representative of

  The outer ring 16 for holding the pressure rollers 14 is freely rotatably mounted in a machine housing and is driven in the relative rotation desired by the rotary hammer shaft 10, in the manner of a differential mechanism. course, between a pair of pressure rollers and the next, the heads

  of hammers and the opening race that results

  give the piece to work the possibility at the same time

  to turn or to move laterally

  However, their use for forming spheres is not obvious because, to date, the rolling method has been applied exclusively to the treatment of cylindrical or conical parts, the forming operation described herein. Above the room can be executed at room temperature

  (cold creep pressing) or also at a temperature

  Increased workload relative to the workpiece (hot pressing) However, preference is given to pressing

  cold, because not only is it less expensive (in

  not at the warm-up operation), but it allows

  highest manufacturing accuracies.

  The trunnion itself 8 'can be achieved by a machining chip removal But he

  It is also possible to bring the trunnion to its de-

final by rolling with rollers.

  Thanks to the invention, it is possible to

  to make ball-type trunnions of the type men-

  in a considerably cheaper way than today and yet to obtain a high quality product. 7.-

R E V E ND I C A T IO N S

  1. Process for the manufacture of tur-

  Spherical taper comprising a rod and a sphere on the end thereof, wherein the sphere is formed by material creep pressing, preferably in a plurality of steps, with the aid of a pressing box and a pressure punch, characterized in that, at least in the last creep pressing step, a press box (1 ') is used for forming the sphere (6'). ) closed and we bring

  then the outer surface of the sphere (6 ') thus Ob-

  held to its imposed size and the degree of polishing desired by a rolling operation galetso

  2. Process according to claim 1,

  characterized in that the pressing casing (11) used

  in the last stage of creep pressing for the

  mage of the sphere has an inner dimension cor-

  corresponding to the imposed dimension of the sphere.

  3. Process according to any one of

  Claim 1 or 2, characterized in that in one

  of the two parts (2 ', 3') which form the casing of pres-

  wise (1 ') is slidably mounted a pressing punch (4') which acts directly on the material constituting the sphere. 4 Process according to any one of

  Claims 1 to 3, characterized in that, at least in

  the last step of the creep pressing operation, the two parts (2, 3 ') forming the pressing casing (1') are assembled together, without an open seal,

  a closed mold and then the punch (4 ') is actuated.