SE412016B - PROCEDURE AND APPARATUS FOR COLD FORMING OF ROLLING ELEMENT - Google Patents

Description

7309581 -2 10 15 20 25 30 35 40 between a larger diameter portion and a portion with smaller diameter, a cylindrical blank is pressed, the outer part of which diameter substantially corresponds to the outer diameter of it rolling elements to be formed, in a matrix whose internal shape is exact corresponds to the desired shape of the surface of the roller element, to provide coming from a transverse flow of the blank, thereby forming the blank in the matrix is interrupted at an exact point, which is the same in following operations.

The device for practicing the invention comprises in essentially a first and a second part, the first part comprises a matrix provided with a molding, whose inner wall has exactly the shape of the surface to be is provided with the roller member, which recess opens, via a conical extension of the inner wall, in a matrix support surface, which is complete plane and perpendicular to the axis of symmetry of the symmetrical of rotation the recess, the matrix having a borehole which elongates the recess in a direction opposite to the planar surface and indicates a diameter which is substantially equal to the smaller one the diameter of the body to be formed, wherein an ejector is slidably arranged in the hole, which ejector cooperates with elastic means, which are arranged directed opposite a force against the ejector depression in the hole, and the other the part comprises a stamp, which has a first support surface, cooperating with the support surface of the matrix, and a second circular support surface, which protrudes from the first support surface and which exhibits exactly the shape you want to give the surface with a larger diameter the body to be formed, which is arranged to penetrate in the said conical extension of the matrix, the matrix and the stamp are arranged to Cörskjutus relative to each other on such that the second support surface of the stamp is retracted into the matrix recess with careful coaxiality towards it until the matrix support surface comes into contact with the first support surface of the stamp.

In the case of the roller means to be produced an axial hole, a starting material having one is used corresponding holes, preferably with a diameter that is slightly larger than the diameter finally obtained, as well as a mandrel which is provided with external polishing elements and which is pushed into the shape of the matrix through the ejector, which for that matter is hollowed out, which mandrel is arranged to be displaced coaxially in the interior of the ejector, the mandrel and its polishing elements 10 15 20 25 -30 40 7309581 -2 has a diameter that exactly corresponds to the desired inner final the hole diameter of the shaped body.

Two embodiments of the invention will now appear described in more detail with reference to the accompanying drawing, in which Fig. 1 shows a diametrical section through a ring whose outer surface has a substantially spherical zone arranged through cold forming in accordance with the invention. Fig. Z shows an analog view of a blank which, after forming, forms a ring according to Fig. 1.

Fig. 3 shows an axial section through a device for forming a ring according to Fig. 1 starting from a blank according to Fig. 2, the device being displayed at the beginning of its operation. Pig. 4 shows an analogous view of the device at the end of its operation.

Pig. 5 shows a vertical view of a roller with an outer conical rotary surface, obtained in accordance with the invention, and, in vertical cuts, interpreters used to control the roll.

Figures 6 and 7 show views analogous to Figures 3 and 4, of a device used for forming the roll according to Fig. 5.

The ring half shown in Fig. 1 is intended for use in a universal type transmission coupling, to together with an additional, identical ring half forming a ring of it type that automatically adjusts, and this ring rolls with its spherical or pseudospheric surface 2, with radius R, on the roller lanes with circular section.

The hole 3 in such a ring rotates around one of the transmission the shafts of the coupling, while the flat surface 4 supports special roundabout (not shown) arranged between the two ring halves 1.

A good feature for a connector that contains this type of ring implies the following requirements for the precision of the ring halves: a) the hole 3 must be given an exact diameter and have a surface condition approaching polished state, b) the spherical zone Z must have a good surface condition, must be fully centered towards the hole 3, and its radius of curvature R must have a precisely determined value and its center must have an accurate adjacent position relative to surface 4, c) the surface 4 must be flat and exactly perpendicular to the hole 3, and the surface 4 must furthermore be exactly located relative to the center of curvature for the spherical or pseudospheric zone 2.

These requirements are well met with the method and the device according to the invention for cold forming.

This device (Fig. 3) comprises a matrix 6 which 1zo9ss1 + 2 10 15 20 25 30 35 40 4 has an axial hole 7 whose diameter is substantially equal with the outer diameter of the surface S of the ring half, while the hole 7 is 'is expanded to form a recess 8 with a spherical surface, wherein the shape of the recess exactly corresponds to the shape of spherical surface 1 of the ring half 2. The recess 8 extends to the upper surface 9 of the matrix 6 via a transition 10 which is slightly conical, for example a conicity at which half the apex angle is in on the order of 5 degrees. in A stamp ll cooperates with the matrix 6, the lower surface 12 of which, which is completely flat is provided with a central projection 13 of circular shape, which also has a completely flat lower surface 14 whose diameter is substantially equal to or slightly less than the outer diameter of the roll 1 to be produced. Stamp ll also has an axial hole 15 whose diameter is slightly larger than the diameter of the ring half 1 hole 3.

The matrix 6 rests on the table 16 to a press, the table has an opening 17 through which a tubular ejector 18 can extend, the outer diameter of which is substantially equal to the diameter of the axial holes 7 of the die 6, while the inner diameter is slightly larger than the diameter of the inner hole of the ring half 1 s. "_ i The ejector 18 comprises at its lower end a flange 19 (Fig. 4) which abuts a helical spring 20 which rests against the bottom 21 of a cylindrical can 22 which is attached to the press table 16 by means of bolts such as 23, which simultaneously serve to holding the matrix 6 on the table 16.

In the interior of the ejector 18 there is a vertically movable mandrel 24 which consists of a cylindrical spindle which at its upper end is slightly rounded at 25 and which at a certain distance. from this rounding have a series of annular beads 26 which form polishing rings. _ The piston 11 is in turn mounted at the outer end of the press piston 27.

The mechanisms and means of controlling the press as well as mandrel 24 is not shown. They are all of the type that are well known to the person skilled in the art and does not form part of the invention.

The described device operates in the following manner.

The starting blank used is shown in Fig. 2. The blank remains of an automatic-turned ring 28 of annealed hard steel. The only the requirement for precision for the use of this substance ring relates to the concentricity of its inner hole 29 relative to its 10 15 20 25 30 35 40 7309581 -2 cylindrical outer surface 30. henna concentricity shall be so good as possible to avoid the finished product shall exhibit irregularities.

The ring 28 has phases 31, 32, 33 and 34 which can achieved by turning or by cold working.

These chamfers are provided for such end products as written and does not show sharp angles but straightened or slightly rounded angles as shown in fig. l.

The piston 27 of the press and the piston 11 are placed at a distance from the matrix 6, and the ejector 18 and the mandrel 24 assume those positions shown in Fig. 3, while the blank 28 lubricated with any suitable means, for example by means of graphite grease, is arranged in the conical the extension 10 of the recess 8 of the matrix, to rest against the the upper edge of the thrower 18, after which the piston 27 is lowered for to allow the stamp 16 for molding to press the blank with force down into the spherical recess 8. During this first tempo, the the blank is held axially at its smaller surface by the ejector 18 which exerts a force F opposite to its compression and this force kept away from the spring 20 which can be replaced by any otherwise known mechanically, hydraulically or pneumatically elastic means, while the hole 29 of the blank is occupied by the cylindrical of the mandrel 24 surface. ' The immersion movement of the piston 27 is continued until the piston lower surface 12 comes into contact with the upper surface 9 of the matrix 6 (Fig. 4), and this abutment ensures precision and a perfect rule dog unit of the final relative to the uadcrytan 14 of the stamp central projection 13 and the spherical surface of the recess 8. The power F exercised by ejectorou 18, on the other hand, is regulated for that the pressure developed by hydrostatic reaction against it spherical surface 8 should be sufficient to provide a correct shaping and surface finish of the spherical surface of the ring half 2. One should here note that the position of the inner surface 5 of the ring may vary depending on the volume of the substance without any inconvenience because this surface does not play a functional role.

Once the outer surface of the ring half is formed, the mandrel 24 is pressed upwards to assume the position 24a which is shown by dotted lines in Fig. 4 after which it is returned to its original position.

The inner hole 3 of the ring is thus perfectly calibrated with precision and polished.

Finally, the press piston 27 was lifted with the piston 11, whereby the ejector 18 moves upwards under the action of the spring 20 to 7309581-2 10 15 20 25 30 35 40 shoot out the finished piece. As mentioned, the invention equally useful for forming rolls or other rotational bodies which do not necessarily have a spherical outer surface, e.g. pelvic conical rollers such as those used in roller bearings.

Fig. 5 shows such a roller 35 which comprises a conical rotation surface 36, the top of the cone being indicated by 0, and a second conical or nearly conical surface 37, the contour of which denoted by 0 ', the generatrix of the surfaces located in the same plane intersect at an angle u of the order of 90 degrees. The top angle of the conical surface 35 is about 13 degrees.

The precision requirements to be met for such rolls are: a) the size of the top angles of the cones, b) exactly coincident axes of these cones; c) the accuracy of the height h measured between two caliber interpreters 38 and 39 consisting of rings whose inner hole edges 40 and 41 respectively comes into contact with the conical surfaces 36 and 37.

Finally, the surface condition of the two cones should be excellent.

The surface 36 with the top 0 occupies the bottom during use the rolling load applied while the cone surface 37 with the top O ' see that the roller in the axial direction is in contact with an edge or flange arranged on one of the roller conveyors. Generatrislängden in the latter cone is arbitrary. The central zone 42 has no functional role and therefore does not need to be manufactured with precision. Likewise, the lower surface 43 of the roller need not be designed with any particular precision as to the position, shape or leveling hot. It can be seen that the surface 37 of the ring is not necessarily must be conical but can be something, for example spherical. _ The device according to the invention for forming the said roller is shown in Fig. 6. The device comprises a matrix 44 which has an axial hole 45 whose upper part is raised to form a recess 46 with a conical surface, the top of the cone angle exactly corresponds to the desired peak angle for con- the surface 36 of the roll to be formed, and amounts to the selected one the example to 13 degrees. The conical recess 46 opens into a recess 47 provided in the upper surface of the matrix 44 and forms a completely flat support surface 48. 4 Interacting with the die 44 is a stamp 49 whose cylindrical outer surface 50 has a diameter corresponding to the diameter of 10 15 20 25 30 35 40 7309581-2 matrix countersink 47. This stamp 49 exhibits at its .completely flat lower surface Sl a central protrusion S2 whose diameter is substantially equal to the diameter of the larger base surface of the roll to be produced, the free surface of the firing 53 has a conical or nearly conical shape which exactly corresponds to the conicity of the surface 37 of the roll to be formed.

Furthermore, the stamp 49 has a channel 54 which extends from the top of the cone surface disposed in the piston 52 surface 53 up to the upper part of the outer surface 50 of the stamp channel 54 serves to divert lubricant applied to the substance in excess before the beginning of its shaping into a conical roll.

The matrix 44 rests on the table 55 to a press at which the table has a central opening through which the ejector 57 extends itself, which consists of a cylindrical piston, which has substantially same diameter as the die 44 holes 45.

This ejector has a threaded end at its lower end portion 58 to which a plate 59 is threaded which plate, in a manner analogous to that shown in connection with the the thrower 18 in the device according to Figures 3 and 4, rests on a spring 60, which in turn rests against the bottom 61 of a sleeve 62 which is attached to the press table S5 by means of bolts such as 63 which at the same time serve to attach the matrix 44 to the table 55.

Regarding the stamp 49, it has at its upper surface a threaded pin 64 which is threaded into a threaded hole 65 which is arranged axially in the piston 66 of the press.

The forming of the roll according to Fig. 5 by means of this device is performed in the following manner.

The starting blank is a cylindrical piece 67 (Fig. 6) of annealed hard steel whose end faces are flat and substantially parallel, wherein the diameter of the cylindrical piece is substantially equal with the diameter of the larger base surface of the roll to be produced and the edges of the blank are chamfered at 68 and 69 to the edges of the ring after forming operations must become blunt or rounded. It is essential that this substance has a diameter which is completely constant over its entire length to the finished the product in turn must have precise dimensions and a shape answering exactly the one you want. 7 To obtain this result, the blanks 67 are arranged through 7309581-2 10 15 20 25 30 35 40 cutting off a cylindrical rod that has previously been surface-cleaned along its entire length.

The suitably lubricated substance is placed in the matrix 44 conical recess 46 so that it rests on the end of the ejector 57 which in the initial position occupies it in fig. 6 showed the situation.

Then the piston 66 of the press is lowered so that the piston 49 projection 52 axially compresses the blank 67 in the conical of the matrix recess 46 under back pressure of the resistive force F (Fig. 7) which is exerted by the ejector 51 due to the action of the spring 60.

The piston 44 is precisely centered during its immersion movement relative to the matrix 44 as it penetrates the recess 47 in the matrix, the bottom of the recess at the end of the movement (fig. 7) stops the lower surface S1 of the stamp in an exact position by the stamp comes into contact with the support surface of the matrix 48. Hereby the precision and constancy of the reference height are guaranteed h between the conical surfaces 36 and 37 of the ring 2, the precision of the angular values of the ring and the surface condition of the cones are guaranteed of the surfaces 46 and 53 on the die 44 and the stamp 49, respectively, while the exact coincidence between the axes of the surfaces is guaranteed of the center 49 of the stamp 49 in the recess 47. g As shown above, the surface precision of the finished product the appearance of the constancy of the diameter of the starting material. Also if you include this necessity, you get a product with remarkable precision and this by means of a simple adjustment of the original rod from which the blanks are cut off the experience of previous procedures for cold forming of rolls of the type mentioned has shown that it does not been possible to obtain such an accurate form and that it has been necessary to individually adjust each piece of format, and such an adjustment of conical pieces, which have relatively small dimensions, is of course in the whole. mvclet longer lasting, more complicated and costly than the adjustment of a simple cylindrical rod.

When the operation of forming the roll, such as that shown in Fig. 1 or Fig. 5 is completed, the roll is cured, for example, by heat curing, and polished by suitable means, for example by passing through a polishing drum.

It should be clear that the two embodiments described above of the invention is by no means limiting and that the invention can be applied for the production of various other pieces by cold forming.

Claims (1)

A method for cold forming a rolling element with constant high-precision dimensions, which element comprises a rotating body whose one end has a larger diameter than its other end, the element having an outer rolling surface with straight or curved generatrices extending between said ends, characterized in that a cylindrical blank whose diameter is substantially equal to the largest diameter of the element is compressed, in a recess in a pad whose inner shape is exactly reproduced on the outer surface of the cold-formed element, against the blank pressure, which is greater than an increasing forming back pressure exerted on the blank, interrupts the depression of the blank in the recess of the pad at a predetermined position, and regulates the back pressure exerted on the blank so that the pressure of the blank against the surface of the pad becomes sufficient. to provide a correct shaping of the outer rolling surface of the cold-formed element. Method according to claim 1 for forming a roller element having a central bore, characterized in that an annular blank is used and that the blank is compressed around a mandrel mounted in the pad, whereby the bore of the blank obtains the dimension of the mandrel, and that the mandrel is displaced for to polish the walls of the bore. 5. A method according to claim 2, characterized in that the concentricity of the bore relative to the periphery of the blank corresponds to the required precision of the finished element with respect to the concentricity between the bore and the outer rolling surface. N. Apparatus for carrying out the method according to claim 1, for cold forming a roller element (1) with constant high-precision dimensions, which element (1) comprises a rotating body whose one end (4) has a larger diameter than its other end (5), wherein the element has an outer rolling surface (2) with straight or curved generatrices extending between said ends, characterized by a pad (6, H4) which has a flat abutment surface (9,48) and a recess (8 , U6) which extends into the pad from the abutment surface and is terminated at a distance from the abutment surface in a cylindrical bore (7, H5) whose axis is perpendicular to the plane of the abutment surface, that the recess has the shape of a rotating body generated around the axis of the bore and has a progressively decreasing diameter in the direction from the abutment surface towards the cylindrical bore, a displaceable ejector (18,57) which is located in the bore and is in contact with a forming back pressure means (20,60) which is arranged to a shaping and force-absorbing movement of the ejector into the bore away from the abutment surface, which force increases with increasing displacement of the ejector away from the abutment surface, a plunger (ll, Ä9) which has an abutment surface (l2.5l) which is arranged to come to abutment against the abutment surface (9, ü8), and a projection (13,52) which extends from the abutment surface of the plunger and is terminated in a circular forming surface (11, 53), the plunger being so shaped that the projection can be accommodated in the recess with the abutment surface of the plunger in contact with the abutment surface of the pad, the circular forming surface of the protrusion being axially separated from the proximal end of the cylindrical bore, and the pad and plunger being mounted for relative displacement along the axis between a position in which the plunger is separated from a pad in which the abutment surface of the plunger is in contact with the abutment surface of the cushion and the projection is accommodated in the recess. Apparatus according to claim H, characterized in that a mandrel (ZA), which is provided with external polishing elements (26) and which extends into the recess of the pad through a bore arranged in the displaceable ejector (7). , is mounted for coaxial movement inside the ejector. Apparatus according to claim U or 5, characterized in that the wall of the recess of the pad has the shape of a part of a sphere or toroid. Apparatus according to claim U or 5, characterized in that the recess of the pad has the shape of a rotary cone. Apparatus according to claim 1, characterized in that the forming back pressure means (20, 60) is an elastic forming means. PROMISED PUBLICATIONS: Germany 56,819 US 1,354,779 (72-354), 1,944,246 (29-90)