WO2009147359A1

WO2009147359A1 - Device for mounting a mandrel in a mill, mill equipped with such a device and mandrel for such a mill

Info

Publication number: WO2009147359A1
Application number: PCT/FR2009/051050
Authority: WO
Inventors: Guy Vinzant; Alain Kaczorek
Original assignee: Guy Vinzant; Alain Kaczorek
Priority date: 2008-06-04
Filing date: 2009-06-03
Publication date: 2009-12-10
Also published as: FR2932105B1; FR2932105A1

Abstract

This device for reversibly mounting a shaping mandrel (12) within a radial cage of a circular mill comprises at least one jaw (210, 212) mounted, with the possibility of radial (Y₁₂) sliding (F₂₁₀, F₂₁₂) with respect to the axis (Z₁₂) of rotation, in a housing (214) capable of rotational movement about this axis, this jaw being provided with a projecting part (2102, 2122) able to fit into an external peripheral groove (1232) of a mandrel head (123) to immobilize this mandrel head relative to the housing. This device also comprises means (216) of loading the jaw (210, 212) in the direction of the axis (Z₁₂) of rotation, a wedge (222) able to move parallel to the axis of rotation and means (224) of driving the translational movement of the wedge in a direction parallel to the axis (Z₁₂) of rotation. The wedge (222) can push (E₂) the jaw (210, 212) in a radial direction (Y₁₂) with respect to the axis of rotation and in a direction (F₂₁₀, F₂₁₂) away from this axis, against the action of the loading means (216), until the projecting part (2102, 2122) of the jaw (210, 212) leaves the groove (1232) of the mandrel head (123).

Description

DEVICE FOR MOUNTING A CHUCK IN A ROLLING MILL, ROLLER EQUIPPED WITH SUCH A DEVICE AND CHUCK FOR SUCH A LAMINOIR

The invention relates to a device for reversibly mounting a shaping mandrel within a radial roll mill cage. The invention also relates to a circular rolling mill equipped with such a reversible mounting device, and to a shaping mandrel that can be used with such a rolling mill.

It is known, for example from FR-A-2014080, to use a circular rolling mill with four rollers for conforming annular pieces. Two cylindrical rollers are used to shape respectively the radial outer and inner faces of the annular piece. The cylindrical shaped roll of the inner radial face of the annular piece is commonly referred to as "mandrel" and has an elongate shape, with a diameter generally smaller than that of the roll used to shape the outer radial face of the workpiece. A pair of tapered rollers is used to shape the front faces of this piece.

A shaping mandrel is a wear part of the rolling mill and its replacement must be provided at regular intervals. In addition, such a mandrel may be damaged during a rolling phase, for example because of a surface irregularity of the workpiece. Mounting such a mandrel in the radial cage of a rolling mill must be reversible, so that the mandrel can be removed and replaced by a new mandrel when needed. To do this, it is known to immobilize the head of a mandrel, that is to say its upper portion in mounted configuration, by means of an axially extending screw. When it is necessary to disassemble the mandrel, this screw is loosened to release the chuck head. However, it is not uncommon for the chuck head to be stuck in position, which requires sometimes dangerous interventions for the staff. For example, some operators lift the mandrel, which weighs several hundred kilograms, using a forklift, before attempting to maneuver, which can cause the accidental fall of the mandrel.

It is these drawbacks that the invention intends to remedy more particularly by proposing a new mounting device whose operation is made reliable. To this end, the invention relates to a device for reversibly mounting a shaping mandrel within a radial roll mill cage, in a configuration where the mandrel is able to rotate about an axis of rotation. This device is characterized in that it comprises:

- At least one jaw mounted, with possibility of radial sliding relative to the aforementioned axis of rotation, in a housing movable in rotation about this axis, this jaw being provided with a projecting portion adapted to be engaged in a groove external device of a chuck head to immobilize the head relative to the housing.

- Loading means of the jaw in the direction of the axis of rotation.

a wedge movable parallel to the axis of rotation, and

means for driving the wedge in translation in a direction parallel to the axis of rotation.

This device is also characterized in that the wedge is able to push the jaw, in a direction radial relative to the axis of rotation and in a direction away from this axis, against the action of the means. load, until clear the protruding portion of the jaw of the groove of the chuck head.

Thanks to the invention, a positive action can be exerted by the wedge to sufficiently distance the jaw or jaws of the chuck head to release it, which limits the risk of accidental blocking.

According to an advantageous aspect of the invention, the wedge is able to exert on a mandrel head an axial release force with respect to the jaw (s). The wedge thus has a dual function, namely to remove the jaw or jaws in order to release the chuck head and drive this chuck head down, as a rule, which makes it possible to overcome a possible seizure situation. .

The device advantageously comprises several jaws distributed around the axis of rotation and the wedge is then able to push all the jaws at the same time, each in a radial direction and in a direction away from the axis of rotation, so that simultaneously detaching their respective projecting portions from the groove of a mandrel head. In particular, two jaws may be arranged on either side of the axis of rotation while being movable according to the same radial direction but in opposite directions, respectively under the action of their respective load means and under the action of the corner.

According to another advantageous aspect of the invention, the wedge comprises a sliding bearing surface on a corresponding surface of the jaw, the bearing surface of the wedge being symmetrical in revolution about the axis of rotation. This allows the corner to interact with the jaw or jaws, regardless of the angular position of the housing and the jaw or jaws around the axis of rotation. In this case, the support surface of the wedge is advantageously frustoconical, while the corresponding surface of the jaw is inclined relative to the direction of sliding of the jaw and the half-angle at the top of the bearing surface of the wedge is equal in absolute value to the angle of inclination of the corresponding surface of the jaw with respect to its direction of sliding. This constructive arrangement allows a sliding support of the corner on the jaw, without risk of matting or damage to the surfaces in contact.

The means for charging the jaw towards the axis of rotation advantageously comprise at least one compression spring.

The invention also relates to a circular rolling mill for the conformation of annular pieces, this mill comprising an outer roll and an internal mandrel, able respectively to shape the radial outer and inner faces of a workpiece, as well as a pair of tapered rollers, respectively lower and upper, able to shape the front faces of this piece. This rolling mill is characterized in that it comprises a device as mentioned above for mounting the mandrel within a radial cage of the rolling mill.

Such a rolling mill is easier to operate and more economical to maintain than those of the state of the art. It is also less dangerous for the staff.

Advantageously, the head of the mandrel is provided with a peripheral groove with a flat-bottomed V-section, while the projecting portion of the or each jaw has a truncated end section with flat lateral faces and that angle of divergence, from the bottom, between the plane edges of the section of the circumferential groove is equal to the angle of convergence of the lateral faces of the section of the protruding part when they are approaching its truncated end. This arrangement allows effective locking of the chuck head by the jaws in the axial cage of the mill.

The invention finally relates to a shaping mandrel for a rolling mill as mentioned above, this mandrel being equipped with a mandrel head provided, on the one hand, with an outer peripheral groove with a V-shaped cross-section at the bottom. flat and, secondly, an axial housing formed in an end face and adapted to receive an end of a corner maneuver.

The invention will be better understood and other advantages thereof will appear more clearly in the light of the following description of an embodiment of a mounting device, a rolling mill and a chuck according to in principle, given solely by way of example and with reference to the accompanying drawings, in which:

- Figure 1 is a schematic representation in side view of a rolling mill according to the invention incorporating a mounting device and a mandrel according to the invention;

- Figure 2 is a partial section along line M-II in Figure 1, the mandrel of the rolling mill being mounted in the radial cage of the mill;

FIG. 3 is a partial perspective view of certain elements represented in FIG. 2;

- Figure 4 is a section along the line IV-IV in Figure 2;

- Figure 5 is a section similar to Figure 2 during removal of the mandrel, only the upper part of the parts shown in Figure 2 being shown;

- Figure 6 is a section similar to Figure 5 in a subsequent step of removing the mandrel;

FIG. 7 is a perspective view of certain elements represented in FIG. 6 and a part of their environment; and

- Figure 8 is a section along the line VIM-VMI in Figure 6.

The rolling mill 1 shown in Figure 1 comprises a main frame 2 on which is mounted a radial cage 3 fixed relative to the frame 2, and an axial cage 4 movable parallel to a longitudinal axis X ₂ of the frame.

The cage 3 carries a roll 10, cylindrical and circular base, rotatably mounted about a vertical axis Zi ₀ and rotated by a motor electric not shown. The cage 3 also carries a secondary roller or mandrel 12 rotatably mounted about an axis Zi ₂ parallel to the axis Zi ₀ , inside a mobile column 14, with respect to a main part 31 of the cage 3 , parallel to the axis X ₂ . The column 14 is supported by bars, only one of which is visible in FIG. 1 with the reference 16 and which can slide relative to the part 31, being driven by motors that are also not shown.

In the present description, the terms "top", "bottom", "upper" and "lower" correspond to the orientation of the parts of the rolling mill 1 when the mandrel 12 is in the configuration of use in the rolling mill. Thus, an "upper" part is located above a "lower" part.

For clarity of the drawing, the cage 3 is shown with a partial cutaway to better visualize the roller 10.

The cage 3 also comprises a plate 17 which defines a housing 171 for receiving the lower end 121 of the mandrel 12, when the column 14 and the plate 17 are aligned vertically, that is to say when the axis Zi ₂ passes through the housing 171. It is then possible to lower the mandrel 12 to engage partially in the housing 171. The housing 171 is visible by partial tearing of the plate 17 in Figure 1. The plate 17 is supported by a carriage 18 movable relative to the portion 31, parallel to the axis X ₂ , and itself supported by bars of which only one is visible in Figure 1, with the reference 19.

The mill 1 also comprises a lower conical roller 20 supported by the axial cage 4 and rotated by a motor not shown. The cage 4 also supports an upper conical roller 22 also driven by a motor not shown. Respectively denote A ₂₀ and A ₂₂ the axes of symmetry and rotation of the rollers 20 and 22. These axes are convergent and approach towards the cage 3.

When a workpiece 100 is in place in the mill 1 and when it is rotated about its central vertical axis Z ^ ₀₀ , it is subjected to radial compression forces Fi and F ₂ exerted respectively by the roller 10 and the mandrel 12, which allows to respectively conform the outer radial surface 101 and the inner radial surface 102 of this part. The intensity of these forces depends on the intensity of the traction exerted on the column 14 and on the plate 17 in the direction of the main part 31.

Furthermore, the roller 22 is vertically movable relative to the frame 41 of the cage 4, being moved by a motor not shown. This allows to exert on the upper end face 103 of the part 100 a force F ₃ directed towards the roll 20, which has the effect of inducing a reaction force F ₄ of the roll 20 on the lower end face 104 of the 100. It is thus possible to exert, directly on the face 103 and indirectly on the face 104 a conformational force of these faces.

In Figure 1, the piece 100 is shown in axial section, while the mill is in side view.

The different moving parts of the rolling mill 1 can be driven by electric motors and / or hydraulic cylinders.

The mandrel 12 is mounted inside the column 14 so as to be rotatable about the axis Z ₁₂ . To do this, the mandrel 12 is engaged in a sleeve 200 pivotally mounted about the axis Zi ₂ relative to the column 14. The sleeve 200 is supported by two roller bearings 202A and 202B themselves supported by a housing 204 immobilized in rotation inside the column 14. The box 204 is closed, respectively in the upper part and in the lower part, by two covers 206 and 207 respectively equipped with rotating joints 208A and 208B. A ring 209 is mounted at the bottom of the sleeve 200, by means of screws, and protects, via two baffles 2091, the lower rotary joint 208B.

An unrepresented motor makes it possible to move box 204 vertically in column 14.

The mandrel 12 comprises a main portion 122 which extends to its lower end 121 and a head 123. The parts 122 and 123 are assembled by screwing. The head 123 is equipped with a central threaded rod 1231 screwed into an axial thread 1221 of the part 122. Alternatively, the parts 122 and 123 may be monobloc, provided that their geometry is in accordance with the meeting of the parts 122 and 123 .

The head 123 is equipped with an external peripheral groove 1232 which is of V-shaped section with a flat bottom, with 1232A and 1232B sides planes and diverging away from the bottom 1232C, with an apex angle α whose value is between 30 and 50 ° preferably of the order of 40 °.

The head 123 is also provided with a hollow housing 1233 formed in its end face 1234, this face being oriented opposite the end 121 of the mandrel 12 in assembled configuration of the parts 122 and 123.

Two jaws 210 and 212 are mounted in a housing 214 each movable along an axis Yi ₂ perpendicular to the axis Zi ₂ , that is to say in a radial direction relative to the axis Zi ₂ . The housing 214 is equipped with a cover 215 which is omitted in FIGS. 3 and 7, for the sake of clarity of the drawing.

The jaw 210 is provided with a cutout in the form of a semicircle and has, at the edge of this cutout, a nose 2102 generally half-circle shaped and intended to engage in the peripheral groove 1232 of the head 123. In the same way, the jaw 212 is provided with a nose 2122 in the shape of a circular arc and intended to engage in the groove 1232. The noses 2102 and 2122 constitute portions of the jaws 210 and 212 projecting radially to the inside, in the direction of the axis Zi ₂ , relative to the main parts 2101 and 2121 of these jaws.

Each of the jaws 210 and 212 is subjected to the action of two springs 216 compressed between the rear face of the jaw 210 or 212 opposite its nose 2102 or 2122 and the housing 214. Thus, the jaws 210 and 212 are loaded by forces Elastics Ei parallel to the direction Yi ₂ and tending to engage and firmly hold the noses 2102 and 2122 in the groove 1232.

The springs 216 are arranged partially inside sockets 218 whose position along the axis Yi ₂ can be adjusted by means of hexagonal heads 220, which makes it possible to adjust the intensity of the forces Ei.

The housing 214 is integral in rotation with the sleeve 200, so that, when the noses 2102 and 2122 are engaged in the groove 1232, the mandrel 122 is secured to the sleeve 200, both in translation and in rotation about the axis. Zi ₂ .

Nos. 2102 and 2122 have a truncated point-shaped cross-section, with lateral faces 2103 and 2104, on the one hand 2123 and 2124 on the other hand, which converge towards the truncated end face 2105 or 2125 of the nose 2102 or 2122, that is to say the internal radial edge of the jaw considered, with a convergence angle β whose value is chosen to be equal to that of the angle α. Thus, nose 2102 and 2122 have a section complementary to that of the groove 1232, which induces a surface support between the jaws 210 and 212, on the one hand, and the head 123, on the other hand.

A wedge 222 is provided axially movable along the axis Zi ₂ , relative to the jaws 210 and 212. This wedge 222 comprises a cylindrical portion 2220 with a circular section and a portion 2222, which forms its lower end, which is frustoconical and 2224 of which is the peripheral area. The parts 2220 and 2222 are centered on the axis Zi ₂ .

Note θ the half-angle at the top of the surface 2224.

A hydraulic jack 224 makes it possible to move the wedge 222 along the axis Zi ₂ . A liner 226 serves as a guide to the wedge 222 in its translational movement between its two up and down end positions shown respectively in Figures 2 and 6. The liner 226 is supported by a plate 228 forming a top cover for an outer housing 230 mounted on the outer portion of the rotary joint 206 and fixed relative to the housing 204.

Alternatively, the cylinder 224 may be electric.

Furthermore, the jaw 210 is provided with a face 2106 inclined relative to the axis Yi ₂ of a non-zero angle δ. In the same way, the jaw 212 is provided with a surface 2126 inclined relative to the axis Yi ₂ as the surface 2106, but in the opposite direction. The angle of inclination δ 'of the surface 2126 with respect to the axis Yi ₂ is opposite to the angle δ. In other words, these angles have the same absolute value but these surfaces are inclined opposite to the axis Yi ₂ .

The surfaces 2106 and 2126 are divergent towards the corner 222, so that the frustoconical end 2222 can be introduced between these surfaces.

For this purpose, the absolute values of the angles θ, on the one hand, and δ and δ ', on the other hand, are chosen equal.

In practice, the surfaces 2106 and 2126 are flat and perpendicular to the plane of section of Figures 2, 5 and 6. Alternatively, the surfaces 2106 and 2126 may be frustoconical, with the same half-angle at the top as the portion 2222.

Each of the jaws 210 and 212 is provided with an excess thickness 2107 or 2127 which makes it possible to give the surfaces 2106 and 2126 a height, that is to say a dimension parallel to the axis Zi ₂ , greater than the thickness of the jaws 210 or 212 in most of its portion which overlaps the surface 1234 in the configuration of Figure 2.

When it is necessary to release the mandrel 12 for a maintenance operation, the wedge 220 is moved towards the end 121, which has the effect of bringing the outer surface 2224 of the portion 2222 against the surfaces 2106 and 2126 jaws 210 and 212 then sliding the surface 2224 on these inclined surfaces 2106 and 2126. This sliding results in a relative separation of the jaws 210 and 212, against the elastic force Ei exerted by each of the springs 216. Indeed , the portion 2222 exerts on the jaws 210 and 212 a radial force E ₂ sufficient to overcome the efforts Ei and move these jaws, as represented by the arrows F ₂₁₀ and F ₂₁₂ .

During this relative radial spacing movement of the jaws 210 and 212, in the radial direction corresponding to the axis Y12 and in opposite directions, the end 2222 of the wedge 222 enters the housing 1233, to the point where the end 2222 comes into contact with the head 123, as shown in Figure 5. In this configuration, the jaws 2102 and 2122 are disengaged from the groove 1232, so that the mandrel 12 can slide along the axis Z ₁₂ under his own weight.

However, by continuing to move the wedge 222 towards the end 121, it can exert on the head 123 an axial force E ₃ and directed towards the end 121, which has the effect of loosening, if necessary, the head 123 and the main portion 122 relative to the sleeve 200.

Thus, the wedge 222 provides a double function of spacing the jaws 210 and 212 and axial thrust on the head 123, which ensures effective unlocking of the mandrel 12, without resorting to hazardous operations or dangerous for the operator.

The housing 1233 is not mandatory insofar as, in the absence of such a housing, a wedge 222 of suitable shape can exert the axial force E ₃ directly on the end face 1234 of the head 123.

The stroke of the wedge 222 and the angles θ and δ are chosen so that the cooperation of the portion 2222 and the jaws 210 and 212 has the effect of clearing the noses 2102 and 2122 of the groove 1232 before the wedge 222 can reach in contact with the head 123. Given the axial direction of the movement F ₂₂₂ of the wedge 222 and the shape of the end 222 with symmetry of revolution about the axis Zi ₂ , the force E ₂ can be effectively transmitted to the 210 and 212 independently of their angular position around the axis Zi ₂ .

When a new mandrel 12 has to be installed in the column 14, it suffices to engage the latter in the sleeve 200 until the groove 1232 of its head 123 is brought to the level of the noses 2102 and 2122, possibly after slightly up the corner 222 to the position of Figure 5. It can then go up the corner 220, that is to say away from the head 123, which has the effect of bringing the nose 2102 and 2122 in the groove 1232, thanks to the efforts Ei exerted by the springs 216. This provides a quick and efficient locking of the mandrel 12 relative to the sleeve 200.

The invention has been shown with two jaws 210 and 212 but can be implemented with jaws in different numbers, these jaws preferably being regularly distributed around the axis of rotation of the mandrel. A variant with a single jaw is conceivable.

Claims

1. Reversible assembly device of a mandrel (12) of conformation within a radial cage (3) of circular rolling mill (1), in a configuration where the mandrel is able to rotate about an axis of rotation ( Z ₁₂ ), characterized in that this device comprises:

- at least one jaw (210, 212) mounted, with possibility of sliding (F210, F212) radial with respect to the axis of rotation (Zi ₂ ), in a housing (214) rotatable about this axis, jaw being provided with a protruding portion (2102, 2122) engageable in an outer peripheral groove (1232) of a chuck head (123) for securing said chuck head relative to the housing

means (216) for loading (Ei) the jaw towards the axis of rotation

a wedge (222) movable parallel to the axis of rotation

means (224) for driving the translational wedge (F222) in a direction parallel to the axis of rotation and in that the wedge (222) is capable of pushing (E ₂ ) the jaw (210, 212) , in a direction (Y ₁₂ ) radial to the axis of rotation and in a direction (F ₂₁₀ , F ₂₁₂ ) away from said axis, against the action (E ₁ ) means of load (216) until the projecting portion (2102, 2122) of the jaw of the groove (1232) of the chuck head is disengaged.

2. Device according to claim 1, characterized in that the wedge is adapted to exert on a head (123) of mandrel (12) an axial force (E ₃ ) of clearance relative to the jaw (210, 212).

3. Device according to one of the preceding claims, characterized in that it comprises several jaws (210, 212) distributed around the axis of rotation (Z ₁₂ ) and in that the corner (222) is able to push (E ₂ ) all the jaws at the same time, each in a radial direction (Y ₁₂ ) and in one direction (F ₂₁₀ , F ₂₁₂ ) away from the axis of rotation, to simultaneously release their projecting parts respective ones (2102, 2122) of the groove (1232) of a mandrel head (123).

4. Device according to claim 3, characterized in that it comprises two jaws (210, 212) arranged on either side of the axis of rotation (Z ₁₂ ) and movable. in the same radial direction (Yi ₂ ) but in opposite directions (F210, F212) respectively under the action of their respective load means (216) and the wedge (222).

5. Device according to one of the preceding claims, characterized in that the wedge (222) comprises a bearing surface (2224) sliding on a corresponding surface (2106, 2126) of the jaw (210, 212), the surface of support of the corner being symmetrical of revolution about the axis of rotation (Zi ₂ ).

6. Device according to claim 5, characterized in that the corresponding surface (2106, 2126) of the jaw (210, 212) is inclined relative to the direction of sliding (Yi ₂ ) of the jaw and in that the half-angle at the top (θ) of the bearing surface (2224) of the wedge in absolute value is equal to the angle of inclination (δ, δ ') of the corresponding surface of the jaw with respect to its direction of sliding.

7. Device according to one of the preceding claims, characterized in that the means for loading the jaw (210, 212) in the direction of the axis (Zi ₂ ) comprise at least one compression spring (216).

8. Circular rolling mill (1) for the conformation of annular pieces (100), this mill comprising an outer roller (10) and an inner mandrel (12), able to shape respectively the outer (101) and inner (102) radial faces. in one piece, and a pair of tapered rollers, respectively lower (20) and upper (22), capable of forming end faces (103, 104) of the part, characterized in that the rolling mill comprises a device ( 200-230) according to one of the preceding claims for mounting the mandrel (12) within a radial cage (3) of the rolling mill.

A rolling mill according to claim 8, characterized in that the chuck head is provided with a flat bottom V-shaped peripheral groove (1232) (1232C), in that the projecting portion (2102, 2122) of the each jaw (210, 212) has a truncated end point section (2105, 2125) and plane lateral faces (2103, 2104, 2123, 2124), and in that the divergence angle (α) from of the bottom, between the edges (1232A, 1232B) of the section of the peripheral groove (1232) is equal to the convergence angle (β) of the lateral faces of the section of the protruding portion when they are close to its truncated end.

10. mandrel (12) of conformation for a rolling mill according to one of claims 8 or 9, characterized in that it is equipped with a mandrel head (123) of an outer peripheral groove (1232) with section V-shaped flat bottom and an axial housing (1233) formed in an end face (1234) and adapted to receive an end (2222) of a maneuvering corner (222).