CH302982A - Process for manufacturing a tubular element and machine for carrying out this process. - Google Patents

Description

Process for manufacturing a tubular element and machine for implementing this process. Methods are already known which make it possible to obtain a tubular element having a bottom, for example in the form of a case, from a cylindrical element of metal.

These known processes consist in compressing this cylindrical metal element between a male pike constituted by a cylindrical punch having the internal diameter of the case and a female part constituted by an equally cylindrical die and whose internal diameter is equal to the outer diameter of the case to be obtained.

The compressed metal is pushed back in the opposite direction to the movement of the punch in the annular space between the punch and the die to form the cylindrical wall of this casing.

This known method only makes it possible to obtain cases of constant thickness over the entire length of the cylindrical wall.

It is also possible to compress the cylindrical element of metal against a fixed punch by means of a rammer sliding inside the die and constituting the bottom of this die.

This known method also only makes it possible to produce cases whose cylindrical wall is of constant thickness.

Dang these two known processes, it is all the more difficult to maintain a good centering of the punch that the case is relatively long.

Other known upsetting methods have two phases. A First Phase in which a thick-walled blank is formed between a punch and a First die and a second Phase in which the cylindrical walls of this blank are elongated in an open die having a step between two bores of different diameters. - rents.

In this known process, which makes it possible to obtain long and well-centered cases, metal particles generally remain in the shoulder of the die connecting the two different bores to each other, which must be removed afterwards. each operation, so as not to scratch the case produced in the following operation; The efficiency of the machine is therefore greatly reduced.

This process, moreover, requires cylindrical starting elements which are of constant volume.

Any difference in volume of this starting element results, in fact, in a difference in the thickness of the base and in a difference in the position of the punch with respect to the matrix at the start of the second phase of the work. .

These differences result in irregularities in the thickness of the cylindrical wall of the case in the vicinity of the fand of this case.

The object of the present invention is to remedy these drawbacks.

It relates to a process for manufacturing a tubular element having a bottom such as cases, sockets, from a solid element such as a billet or extruded bar, process comprising a phase of forming a hollow-shaped blank and a Elongation phase of this blank, characterized in that the blank is formed, in the First Phase, by spinning the metal of the solid element in the annular space provided between a female member and a fixed axial member, the second phase being carried out by stretching the cylindrical walls of the blank in this same female member by the axial member moving relative to the female member bearing on the bottom of the blank.

The spinning of the metal of the solid element dann the open annular space between the female member and the axial member can be achieved by compressing this metal in this female member by means of a follower forming a piston.

The drawing phase of the blank can be carried out by resting the axial member on the bottom of this blank and by relative displacement of this axial member with respect to the female member, and in this female member , the edges of the blank being pinched between this female member and the axial member.

The invention also relates to a cylinder for implementing the method which is the subject of the invention, characterized in that it comprises on a common frame two opposing coaxial press cylinders in which two press pistons move. , the upper piston being integral with the axial member, the lower piston being integral with a rammer.

The female member can be fixed to the upper cylinder, which makes it easier to achieve the centering of this female member relative to the axial member, that is to say the regularity of the annular space between the female organ and the axial organ.

The female member may be constituted by an open die having internally on the side of the gland a cylindrical bore forming a cylinder for this gland, an annular part, narrowed, with respect to the cylindrical of the axial organ. The upper cylinder may have an upper bottom engaged in this cylinder in a sliding manner, this bottom being integral, via the driving fluid inlet nozzle, with a cap screwed externally on the cylinder, which makes it possible to adjust the stop constituted by this movable bottom.

The attached drawing shows, by way of example, one embodiment of the machine for carrying out the process, which is the subject of the invention.

fig. 1 is an axial sectional view of the machine in its starting position.

fig. 2 is an axial sectional view of this same machine after the First Phase of work.

fig. 3 is an axial sectional view of this same machine after the second phase of work.

fig. 4 is an axial sectional view of the machine during the ejection phase of the finished case.

fig. 5 is a cross-sectional view, to larger scale, of the female organ.

fig. 6 is a schematic view of the entire machine.

Figs. 7 and 8 are sectional and plan views of the extraction device.

The jaw shown in Figs. 1 to 4 comprises the following essential elements: a) An upper press cylinder 2 fixed in the frame 1 of a press.

This upper cylinder 2 has a flange 3 resting in a bed base 4- in the form of a ring embedded in the frame 1.

Urre flange 5 with threaded flange 6 and shoulder 7 bears by this shoulder against the flange 3 of the upper cylinder 2. The flange 5 has holes through which pass studs 8 screwed into the frame 1. Nuts 9 screw on these studs 8 bear against the flange 5, which, through the intermediary of the shoulder 7, clamps the flange 3 of the cylinder in the bed base 4 and ensures the solid fixing of the cylinder 2 in the frame 1.

The upper cylinder 2 is arranged verti- calem.ent and its axis XX' is Faxe of the ma chirre or axis of work. At its upper part, the cylinder 2 is closed by a movable bottom 10 slidably engaged in the bore of this cylinder 2. This bottom 10 comprises, on the inside, a peripheral housing in which is placed a seal 11 U-shaped section. This bottom 10 pierced with an axial hole 12 is integral, via a fluid inlet nozzle 13, with a cap 14 screwed onto an outer thread of the cylinder 2.

By screwing or unscrewing the cap 14, an adjusts the position of the bottom 10 in the cylinder 2.

At its lower part, the cylinder 2 comprises an internal shoulder 15 forming a bottom in which the rod of the piston which will be described later slides freely.

This shoulder is pierced with a radial Banal 30 extended by a fluid inlet nozzle 31.

The seal between this stem and this bottom is ensured by a seal 16 with a U-section placed in a housing of the shoulder 15 on the outside side.

b) A die holder 17 of generally tubular shape comprising an upper part in the form of a sleeve 18 engaged on the lower part of the cylinder 2, and screwed by an external thread into a thread of the collar 6 of the flange 5.

The sleeve 18 has internal shoulders 19-21. The shoulder 19 rests on a washer 20 holding the seal 16 in its housing.

The shoulder 21 rests on an annular pike 22 having on the inside a housing for a seal 23 with a U-section applied against the piston rod. The annular pike 22 is itself applied against the washer 20 via a ring 24 pierced with two opposite radial holes 25-26. This ring 24 determines, around the piston rod, an annular cooling chamber 27.

The sleeve 18 is pierced with two diametral channels 28-29 opposite the opposite holes 25-26 of the auneau 24. The Gage 17 comprises at its lower part a ring 32 having a square section with a threaded outer surface 33.

Internally, the ring 32 has two bores of different diameters 34-35 strictly centered on the axis XX' and a flat shoulder 36 connecting these two bores and strictly perpendicular to this axis XX'.

The cage 17 is hollowed out longitudinally between the sleeve 18 and the lower ring 32, these openings making it possible to monitor the work of the machine from the outside and to limit the transmission of heat by conductibility between the die. and the press cylinder.

c) A die or die 37 (Fig. 5) fixed to the lower ring 32 of the die holder cage.

This die 37 of generally tubular shape has on the outside, at its upper part, two smooth bearing surfaces 38-39 of different diameters and a flat shoulder 40 (FIG. 2) corresponding to the bores 34-35 and to the shoulder 36 of ring 32.

This die is thus applied by these bearing surfaces and shoulders in the corresponding part of the ring 32. It is fixed on this ring 32 by a ring 41 engaged around this die 37, screwed onto the externally threaded bearing surface 33 of this ring and supported by an internal shoulder 42 on a corresponding external shoulder 43 of the die 37.

Internally, die 37 has a working surface comprising from bottom to top: a wide open conical surface 44, a cylindrical bore 45 of significant length and diameter D.

a cylindrical bore 46 of short length and of diameter D1 slightly less than the diameter D, a fillet 47 with a large radius.

The bearing port 40 of the die must be strictly perpendicular to the axis of this die, so that the bores 45 and 46 are strictly centers if the working axis, Xg'; Around the die 37 is placed a heat generator constituted, for example, by an electrical resistor 48 of annular shape.

d) A spinning needle 49 has the lower end slightly tapered and forms the shape to be formed inside the case.

In the case of the example shown, this needle has, at its lower part, rounded edges 50 and an axial depression 51.

The needle 49 is screwed through the upper part of the rod Jans a press piston 50 sliding in the upper press cylinder 2.

The rod of the needle 49 is cylindrical in shape and it slides tightly in the seals 16-23 of the cylinder 2 and of the cage 17. The diameter D4 of this rod is slightly smaller than the diameter D1 of the bore 46 of the die.

The press piston 50 comprises on each of its faces an annular housing 51-52 in which is placed a U-shaped seal 53-54.

e) A rammer 55 centered on the working axis XX' and integral with a press piston 56 similar to the upper piston 50. This lower piston 56 moves in a lower press cylinder 57 similar to the upper press cylinder 2, this lower cylinder being fixed to the common frame 1 of the press (FIG. 6).

The control of the fluid controlling the movement of the upper and lower pistons is carried out independently, which makes it possible to give the needle 49 and the follower 55 independent movements.

The gland 55 has a cylindrical stem terminated at its upper part by a bead 58 of diameter D2 slightly greater than the diameter D3 of the stem and slightly less than the diameter D of the bore 45 of the die, so as to be able to slide with gentle friction in this bore 45 (fig. 5).

The machirre described above works as follows: 1 Mine in working position (fig. 1). The needle 49 is in its high position, the piston 50 abuts against the movable bottom 10 of the cylinder 2, adjusted to the appropriate position by screwing or unscrewing the cap 14.

In this position, the tip of the needle is engaged in the bore 45 of the die. Rammer 55 is in its up position. 0n place on this rammer 55 the starting element, which is constituted by a section of bar or cylindrical billet 60, adopts the diameter is approximately that of the case to obtain.

The Billet 60 is preheated and coated with graphite oil.

2 Wiring the case (fig. 2).

The motor fluid is sent to the lower part of the lower cylinder 57, the lower piston 56 rises at the same time as the rammer 55 carrying the Billet 60.

This Billet is pushed into the die 37 by the rammer 55 which engages in this die following this Billet.

The Billette 60 crashes on the Pointe de l'aiguille dopt it marries the relief.

The movement of the rammer 55 continuing upwards, the bead 58 of this rammer forms a piston in the bore 45 of the die which constitutes the cylinder, and the metal of the billet 60 is spun upwards through the annular space 61 existing between the needle 49 and the bore 46 of the die.

At the end of the upward stroke of the rammer 55, an obtains the blank 62 of a case, covering the tip of the needle 49 and matching the shape of the last rette.

3 Drawing the case blank (fig. 3). By introducing the motive fluid to the upper part of the lower cylinder 57 and by exhausting the lower part of this cylinder, an moves downwards the piston 56 and the follower 55 which then emerges from the blank. 62 of the case.

The working fluid is then introduced through the nozzle 13 at the upper part of the upper cylinder 2, which produces the downward displacement of the piston 50 and the needle 49. This needle 49 is lowered until the position represented in fig. 3, 3a rod sliding in the bore 46 of the die 37, in this movement, the cylindrical part of the blank 62 of the case is stretched between the conical point of the needle 49, playing the role of mandrel and the 46 bore of reduced diameter, playing the drawing bezel Ale.

At the end of the downward stroke of the needle 49, the case 63 has a cylindrical outer shape of diameter D1 and an inner shape corresponding to the shape of the tip of the needle 49.

This case caps the tip of this needle 49 which must project downwards, through the needle 37 (fig. 3).

4 Removal of the case (fig. 4).

A U-shaped extractor 64 (fig. 7 and 8) and whose internal diameter is slightly greater than the diameter D4 of the shank of the needle 49 is engaged on this shank between the die 37 and the case 63.

Motive fluid is then admitted to the lower part of cylinder 2 to move piston 50 and needle 49 upwards. the needle continues its upward movement.

The machine is thus in its starting position and ready for a new operation.

The motor fluid admitted or evacuated by the nozzles 13-31 of the cylinder 2 can be in liquid such as oil or a gas such as compressed air.

The intake and exhaust control is effected by means of distributors of known types.

The control of the arrival and evacuation of the motor fluid in each cylinder can be carried out in such a way as to obtain: a rapid stroke while the force exerted is low; a slower course While working effort is exerted.

Thus, the follower 55-58 will quickly bring the billet 60 against the point of the needle 49, then will move slowly and following a reduced stroke to spin the metal from the billet 60. rammer 55-58 out of the lifeline will be done quickly.

The ascent stroke of the needle 49 through the die 37, and during which the extraction of the finished case occurs, does not require effort and will be carried out quickly.

Finally, the descent of the needle through the die to produce the drawing of the blank requires much less labor than the spinning of the blank through the rammer. The upper cylinder 2 may have a section much smaller than that of the lower cylinder 57 and the downward stroke of the needle 49 may be carried out much more quickly than the upward stroke of the gland 55.

In the annular space 27 surrounding the stem of the needle 49, cooling water must circulate, arriving through one of the conduits 28-29 and leaving through the other. The rod of this needle is thus cooled, which reduces the heat transmitted by conductivity from the tip of this needle 49 to the piston 50, to the cylinder 2 and to the sealing linings.

In the above-described machine, the needle 49 is advantageously made up of a single pike, which makes it possible to achieve very good centering of this needle 49 in the die.

The cases obtained also have cylindrical walls of very regular thickness. The process described can also, for certain metals such as aluminium, be employed without external heating of the die 37. The circulation of water in the annular space 27 can however be maintained to avoid the transmission heat from metal working to seals.

A lubrication by spraying is, in this case, provided above the die 37.

The process described applies in turn to metals or alloys capable of being deformed when hot or cold, such as brass, copper, aluminum bronze, mild or semi-hard steel, aluminium, light alloys, magnesium alloys, etc.

For the hot working of brass, steel and generally metals working at more than 500 C, a well-mixed mixture composed of:

Linseed oil 2 parts by weight Crystalline graphite 1 For hot working of aluminium, light alloys and generally metals working at less than 500°C, use a well mixed mixture consisting of:

Mineral quenching oil 2 Parts by weight Crystalline graphite 1 The mineral quenching oil will preferably contain 10 to 20% rapeseed oil.

The conformation work can be facilitated by adding 10% by weight of linseed oil to the mineral oil mixed with the crystalline graphite.

In the case of cold working a metal such as aluminum, an coats the starting billet with a viscous mineral oil such as that normally used for lubricating the rear axle gears of motor cars.

Choose an oil that adheres well to the metal to resist the washing produced by the runoff of the necessary cooling water, as mentioned above.

The various lubricating means described above make it possible to carry out the operations for shaping the metal described above, without the risk of tearing or wrinkling of this metal.

The process described has, vis-à-vis the known processes, the following technical advantages: female organ 37. The machine is therefore simpler than most known machines. 2 The female organ has no internal shoulder liable to retain particles of mkal and which must be cleaned after each operation.

3 Billet 60 used as a starting element has substantially the diameter of the finished case and can be cut from a bar of relatively small section. This reduces the loss of mkal by sawing or cutting the bar.

4 The process makes it possible to obtain cases of cylindrical external shape, but of conical internal shape.

The bottom of this case can moreover present both externally and internally any desired relief. It suffices that the corresponding hollow be formed on the end face of the needle 49 or on the end face of the rammer 55-58.

5 The First Phase is carried out by crushing the Billet on the end of the needle 49, that is to say by compression and discharge of the metal from the Billet 60 through the rammer 55-58.

The second phase is carried out by stretching the blank, the bottom is pushed by needle 49 and the edges are pinched in the stretching slot formed between the female member 37 and the conical surface of this needle.

In both phases, the metal is deformed parallel to the direction of movement of the movable member and in the same direction as that movement, resulting in perfectly strong cylindrical walls.

6 The process described combining a rolling operation with a pulling operation makes it possible to obtain in a single pressing operation a tubular element whose walls are thinner than those of the element which could be produced in a rolling operation. - single width.

Claims (22)

CLAIMS: I. Method of manufacturing a tubular element having in. bottom from a solid element, method comprising a Phase of forming a blank of hollow shape and a Phase of elongation of the blank, characterized in that the blank is formed in the First Phase by spinning of the metal of the solid element in the open annular space provided between a female member and a fixed axial member, the second phase being carried out by stretching the cylindrical walls of the blank in this same female member, by the the axial member moving relative to the female member and resting on the bottom of the blank. II. Machine for carrying out the process according to claim I, characterized in that it comprises on a common frame two opposite coaxial press cylinders in which two press pistons move, the upper piston being integral of the axial member, the lower piston being integral with a rammer. SUB-CLAIMS: 1. Process according to claim I, characterized in that the spinning of the metal of the solid element in the open annular space is carried out by compressing the metal in the female organ by means of of a rammer forming a piston. 2. Process according to claim I and sub-claim 1, characterized in that the drawing phase of the blank is carried out by pressing the axial member on the bottom of said blank and by relative displacement of the gold - axial gange with respect to the female member and Jans the female member, the edges of the blank being pinched between the female member and the axial member. 3. Process according to claim I, characterized in that the finished tubular element is detached from the axial member on which it is shaped and to which it adheres, during the ascent of the axial member towards its position. initial, by abutment of the edge of said element against a retaining member. 4. Process according to claim 3, characterized in that the retaining member is slid around the axial member between the edge of the tubular element engaged nur the axial member and the female member. 5. Process according to claim 1, characterized in that a mixture of one part by weight of crystalline graphite and two parts by weight of oil is used for the lubrication of the elements. 6. Process according to sub-claim 5, characterized in that for the hot working of metals working at more than 500° C., linseed oil is used. 7. Process according to sub-claim 5, characterized in that for the hot working of metals working at less than 500° C., a quenching mineral oil is used. B. Process according to sub-claim 7, characterized in that linseed oil is added to the quenching mineral oil. 9. Process according to sub-claim 7, characterized in that rapeseed oil is added to the quenching mineral oil. 10. Process according to claim 1, characterized in that an oil of the Gelle type used for the rear axles of motor vehicles is used for the lubrication of the cold-worked solid element. 11. Machine according to claim II, characterized in that the female member is fixed to the cylinder, in which the upper piston moves. 12. Machine according to claim II, characterized in that the female member is constituted by an open die having internally on the side of the rammer a cylindrical bore forming a cylinder for this rammer, an annular part narrowed with respect to the cylindrical bore following to this bore of the AM of the axial member. 13. Machine according to sub-claim 12, characterized in that the bores of the female member are extended on the outside side by flared parts. 14. Machine according to sub-claim 12, characterized in that the die is mounted in the lower part of a cage fixed by its upper part to the upper cylinder itself fixed to the frame of the press. 15. Machine according to sub-revendieation 14, characterized in that the die is fixed in a lower ring of the cage by a ring surrounding the die, screwed onto the lower ring and clamping the die against said ring. 16. Machine according to sub-claim 14, characterized in that the cage has at its upper part a sleeve engaged on the lower part of the upper cylinder and screws into the collar of a flange immobilizing the cylinder on the frame. 17. Machine according to sub-claim 16, characterized in that the flange bears by a shoulder on a collar of the upper cylinder and applies this collar to a bed base arranged in a housing provided in the frame. 18. Machine according to sub-claim 17, characterized in that the upper cylinder has an upper bottom engaged in this cylinder in a sliding manner, said bottom being integral, via the inlet nozzle of the motor fluid, a cap screwed on the outside of the cylinder, which makes it possible to adjust the stop formed by this mobile bottom. 19. Machine according to sub-claim 14, characterized in that the cage clamps against the bottom adjacent to the upper cylinder sealing gaskets applied against the axial member and forming between them a chamber for circulation. dun cooling fluid around the axial member. 20. Machine according to claim II, characterized in that the axial member is constituted by a needle with a cylindrical rod fixed to the upper piston, the end part of this needle being slightly conical and having at the end and hollow, the relief to be made in the bottom of the tubular element. 21. Machine according to claim II and sub-claim 12, characterized in that the rammer consists of a cylindrical rod terminated at its upper part by a bead of larger diameter and capable of sliding like a piston. in the cylindrical bore of the die. 22. Machine according to claim II and sub-claim 12, characterized in that the die is surrounded by heating means constituted by an electrical resistor.