FR2554743A1 - Forming head for longitudinal splines over the whole periphery of cylindrical pieces - Google Patents

Abstract

The device according to the invention makes it possible to produce a relatively small tooling equipment which is durable and which can take very large loadings. The present invention comprises shaped roller bearings 21 which are mounted annularly onto a toric shaft 16. This unit of assembled shaped roller bearings and toric shaft is mounted in a cage-shell 3-4 which allows the passage 17 of the roller bearings to the selected positions. This unit thus produced is inserted into a cone-shaped hoop 2 in such a way that the stress exerted at the time of mounting is identical to that exerted when a load is applied, thereby preventing any bending and maintaining good accuracy. The device according to the invention is particularly intended for the production of mechanical pieces used in transmission members and rigid couplings.

Description

Forming head for longitudinal grooves on the entire periphery of cylindrical parts.

 The present invention relates to a tool for forming longitudinal grooves: inals or of various shapes on cylindrical parts, by cold stamping on parts made of full material or by shrinking and rolling for sheet metal parts.

 This tool is mounted on a vertical press for short pieces. For very long parts it is mounted on a horizontal hydraulic press.

 We contact forming tools for the lamination of hydraulic parts. In all these tools, a number of profiled rollers is used corresponding to the number of lurex rods, arranged in a circle, perpendicularly around the part and brought into contact simultaneously.

The rolling forces are absorbed by the rollers; these rollers are supported in different ways
a) on large bearings with corresponding rollers which increases the rolling effort-by the surface in contact with the part.

 b) on a series of rollers mounted in support and in rotation on independent axes which considerably increases the size of the tools.

 c) by a sliding constraint ring used to react the rollers.

 d) there are also devices intended to laminate tooth profiles and comprising several rolling tools arranged in a circle around the part. These tools are supported on tongues which are housed in grooves formed in an annular bearing body.

At the same time, the cylinders roll on the tabs. The rolling tools, as well as the workpiece, therefore move in the rolling direction.

 In all known systems, the rolling force is always reacted by an opposite point of tangency, resulting in premature wear of the functional parts.

 The device according to the invention makes it possible to obtain a tool with low wear, of small size, accepting very heavy loads, which can be used on standard machines and incorporated in production units for very large series.

 the present invention comprises profiled bearings (21) according to the shape to be obtained. They are mounted annularly on a toroidal axis (16) in two clevetted parts (10).

 This assembly, profiled bearings and O-ring assembled, is mounted in a shell cage (3-4) in two perforated parts so as to allow the passage (17) of the bearings in the chosen positions, and in which the location will have been machined. torus.

 This assembly thus produced is inserted into a conical hoop (2) so that the stress exerted at the time of assembly is identical to that exerted at the time of the effort, this in order to avoid any bending and to maintain good accuracy. .

Different variants can intervene on this tool in specific cases
I) For tormented and very precise profiles, a second row of bearings is executed alternately under the first. Each row thus allows a phase of the operation: 1st row bottom form (18) and 2nd row calibration top form (19).

II) For stamped sheet metal parts with a bottom, it is possible to obtain a partial lining (13) and simultaneous with the forming operation. For this dubbing phase just
- Modify the upper mandrel (6) to a dimension capable of supporting this double thickness according to the desired length (13).

 - Provide a stamped part of larger dimension (12) so as to cause a creep and an overflow of material on the upper mandrel (6) so that the passage of the bearings (21) this double thickness is stamped.

 III) This invention also allows a dimensional adjustment in order to perfect the dimensions. This adjustment can be made by the inner ring (a) of the bearing.

This ring is machined in its bore so that it follows the shape of the torus (16). The machining of the outer part of this ring (8) is eccentric relative to its axis; the adjustment is carried out by turning this ring according to markings and immobilizing it in the chosen position.

 IV) We can also provide a circular axis of another geometric shape such as a hexagon or a circular octagon. It will suffice for this to provide an identical passage in the inner ring (e) and on the shell-cages (3-4).

This system makes it possible to avoid immobilizing the ring (s) while retaining several adjustment positions.

V) This invention offers us another possibility with regard to stamped sheet metal parts with a maximum height of fifty millimeters.
By off-centering the active part (7) of the bearing (21) it is possible to obtain, on the outside of the part, a slightly conical shape, positive or negative, thus making it possible to compensate for a relaxation of the material.

 VI) It is also possible, by choosing another point of the bearing, to obtain a concave or convex curve.

This lifting curve, in the case of a rim for toothed pulley; improves the grip of the belt.

 It is nevertheless necessary to provide, using a tension spring, a system for returning the bearings to their initial positions.

 The appended drawings, FIG. 1 and FIG. 2, describe by an example of use, the production of grooves on a stamped tGle part and, as a variant, a grooved lining (12 and 13).

 Figure n01 shows a sectional view along 3.3.

 Figure 2 shows a partial sectional view along A.A.

Figure 1 shows the closed tool, we can see the following marks
- In a sole (1) an openwork is shaped in the profile of the mandrel (5). The latter is placed sliding in the aperture and permanently stressed in the direction of the arrow (15) in order to be placed open tool at the level of the magpie, this to be transformed into a sbematized gar (20).

 - In opposition to the mandrel (5) the upper mandrel (6), actuated by the sliding of a press, moves up and down during forming, then rises with less force to the open tool position.

 - On the sole (15 concentrically mandrel (5) is fixed by screws (îi) a hoop (2) of sufficient strength to maintain the cage-shells (3-4) under stress.

 - In the shell cages (3-4) is mounted a rolling pin (16) in two parts joined by two keys (10).

On this axis are mounted the profile bearings (21).

 - These bearings consist of a profiled outer cage (7), a row of rollers (9) allowing the rotation and the distribution of the force on an inner ring (8) adjusted on the toric axis (16).

 - The dimension of these bearings is calibrated so that the engagement ramp is sufficiently weak to avoid a significant opposing force on the one hand, and, on the other hand, for a choice of direction of the axial forces.

the tool with this type of part works in the following way
At the end of the cycle, the upper mandrel (6) is always removed from the tool to allow the passage of the part to be formed. The mandrel (5) under the action of the pressure of the lower cushion is placed in the high position (20). Then place the part 'to be executed (2C).

 during forming, the mandrel (63 descends, actuated by the press and clears the lower pressure (15) by pushing on the part (20). The latter comes into contact with the rollers then engages in the profiled rollers (7 ) themselves go into rotation on the rollers (9) by the thrust exerted on the material to be deformed during rolling.

 By using a stamped part of a larger dimension (12), variable as a function of the height of the reversal (13), there is a bending at the level of the zone at the time of contact with the bearings (21). ), a constriction at the point of contact with the bearings (21) and a re-entry force greater than @@ force necessary to push the zone (12) into the inversion position.

 this moment, the penetration force becomes substantially identical, the part engages in the bearing and the tool ends its cycle.

 An ejection system is provided for extracting the part from the mandrels by a pneumatic system according to the equipment of the work station.

Claims (1)

 I) forming head for groove on the entire periphery of the cylindrical parts, characterized by a quantity of bearings (7) which are buried, annularly rotatably mounted on a toric or octagonal circular fixed axis (16), on which the adjustable rings are mounted ( s); the assembly is placed in a support cage (3-4), reacted by a conical hoop (2) agizzar.t by constraint at the time of mounting on the interior support elements (3-4-16).  i) Tool according to claim No. 1 characterized in that the bearings have a large number of rollers allowing a distribution of the dynamic load calculated at double the effort required thus allowing very high viability.  III) Tool according to claim No. 1 characterized by a toric axis (16) thus increasing the contact surface and allowing good retransmission of the forces on the cage-shells (3-4).  IV) Tool according to claim n0 i characterized by a ring (8) fitted clamped between the supporting fabrics (22) thus preventing any buckling of these fabrics.  V) Tool according to claim n0 i characterized by a conical flange hoop (2) acting by constraint on all the load-bearing elements thus avoiding any play over time.  VI) Tool according to claim No. 1 allowing adjustment of the dimensions by acting on the ring (8).  VII) Tool according to claim No. 1 characterized in that by a rectilinear movement we obtain different shapes (conical, positive or negative, concave or convex) by shaping the outer cage of the bearing (7) eccentric and choosing on the involute of the circle the shape to obtain on the part.  VIII) Tool according to claim No. I characterized by a double operation of simultaneous turning and fluting, thereby improving the molecular structure of the material and the cost of production.  IX) Tool according to claim No. 1 characterized in that one can superimpose two alternating heads making it possible in all cases to carry out fluting and stamping in a single operation, bottom of form (19) and top of form (18 ).