DEVICE FOR TREATING, BY HEAT TEMPERING, A METAL ELEMENT OF THE TUBE OR BAR TYPE HAVING ARCHED PORTIONS

Abstract

The invention relates to a device for treating, by heat tempering, a metal element (1) of the tube or bar type having arched portions. The device includes heat treatment means having an induction coil (23) and a sprinkler ring (26). According to the invention, this device includes means (2) for holding the metal element (1) that is composed of a clip (2) arranged so as to clamp around an end portion, referred to as the top, of the metal element and to keep the metal element freely suspended under said clip. The device also includes multi-axis robots (24, 28) suitable for moving the induction coil (23) and the sprinkler ring (26) simultaneously along the metal element (1) starting from an end portion, referred to as the bottom, of the metal element that is opposite the top portion thereof.

Claims

1. A thermal quenching treatment device of a metal element, of the tube or bar type, having curved sections, comprising: a heat treatment device comprising an induction coil and a cooling device comprising spray nozzles integrated into an annular sprinkler ring, a holding device for the metal element, and a displacement device, the holding device and the heat treatment device are adapted to produce a relative displacement of the metal element inside the induction coil, and the annular sprinkler ring is arranged in close proximity to both the holding device and the heat treatment device, the holding device for maintaining the metal element is composed of a clamp arranged in such a way as to tighten a stretch of an end of the metal element, and to maintain the metal element freely suspended under the clamp, and there is provided a travel device that is capable of simultaneously moving the induction coil and the annular sprinkler ring along the metal element suspended under the clamp, from an end section of the metal element opposite to an upper section.

2. The thermal quenching treatment device according to claim 1, wherein the clamp retaining the metal element is carried by a rotational drive of the clamp around a rotation axis (x), capable of conferring an oscillation motion at the metal element suspended under the clamp.

3. The thermal quenching treatment device according to claim 1, wherein the clamp retaining the metal element is carried by displacement of the clamp according to at least one axis of translation.

4. The thermal quenching treatment device according to claim 3, wherein rotational drive of the clamp is around an axis of rotation (x) carried by movement of the clamp according to a vertical translation axis (z) and a horizontal translation axis (y).

5. The thermal quenching treatment device according to claim 1, further comprising a rotating drive of the clamp around a vertical axis (z).

6. The thermal quenching treatment device according to claim 1, wherein a displacement of the induction coil is adapted so that a center of a plane that is transverse of the induction coil is at least substantially coaxial with a median plane of a neutral fiber Fn of the metallic element.

7. The thermal quenching treatment device according to claim 1, wherein the induction coil and the annular sprinkler ring are carried by a multi-axis robot.

8. The thermal quenching treatment device according to claim 1, further comprising a multi-axis robot unloading with a clamp for the attachment of the metal element after heat treatment.

9. The thermal quenching treatment device according to claim 1, wherein the clamp retaining the metal element consists of a tubular clamp suitable for styling and tightening the upper section of the metal element and extending into an axial extension of the upper section.

10. The heat treatment device according to claim 9, wherein the clamp has an external diameter lower than respective internal diameters of the induction coil and the sprinkler ring, suitable to allow axial displacement of the induction coil and the annular sprinkler ring along the clamp.

11. The thermal quenching treatment device according to claim 1, wherein the heat treatment device includes a source of cold fluid connected in such a way as to inject a cold fluid flow into an end section of the metal element, during the heat treatment.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Other features and advantages of the invention will become apparent from the detailed description which follows with reference to the accompanying drawings which show, by way of non-limiting example, a preferred embodiment. On these drawings:

[0020] FIG. 1 is a schematic perspective view of a thermal quenching treatment device according to the invention;

[0021] FIG. 2 is a perspective view of the means of this device for processing, holding and moving a metal element:

[0022] FIG. 3 is a longitudinal section through an axial plane of the clamp for holding a metal element and means for heat treatment of this metal element, represented positioned at the end of the treatment operation:

[0023] FIG. 4 is a cross section through a plane A of FIG. 3; and

[0024] FIG. 5 is an explanatory diagram of the mode of displacement of the induction coil.

DETAILED DESCRIPTION OF THE INVENTION

[0025] The treatment device according to the invention shown in the figures consists of a device for heat-quenching treatment of a metal element of the bar or tube type, such as a suspension element of a motor vehicle, which may notably consist of: shown in a torsion bar 1.

[0026] This thermal quenching treatment device comprises a holding device 2 for holding the metal element 1. The holding device 2 is composed of a clamp arranged to be positioned in the vicinity of an end section, the upper end, of the metal element so that the metal element 1 is kept freely suspended under the clamp. The thermal quenching treatment device also includes displacement devices for moving the clamp 2, on the one hand, in translation along a vertical axis (z) and along a horizontal axis (y), and on the other hand, in rotation around the vertical axis (z) and around a horizontal axis (x) perpendicular to the plane (y, z).

[0027] In the first place, the clamp consists of a tubular clamp 2 of the type of free cutting pliers comprising a part of revolution partially split along several generatrices, allowing, by its elasticity, to tighten on the outside of a cylindrical part of the metal element 1. In the example shown, this clamp 2 comprises an outer tube 10 having a flared end forming a conical seat 11 and an inner tube 12 pierced with a longitudinal axial bore 13. The longitudinal axial bore 13 is extended by a conical head 14 adapted to be housed in the seat 11 of the outer tube 10. The conical head 14 is provided with four radial slots such as to give it its elasticity. The conical head 14 has a front face in which is formed a countersink 16 for clamping the end of the metal element 1, and a displacement device for relative displacement of the outer tube 10 and the inner tube 12 between a loading position of a metal element 1 in the counterbore 16, in which the conical head 14 extends in the extension of the outer tube 10, and a clamping position of the end of the metal element 1, in which the conical head 14 is clamped in the conical seat 11.

[0028] In addition, the displacement device of the outer tube 10 and the inner tube 12 is adapted to move the outer tube 10 longitudinally along the inner tube 12. The displacement device consists of a jack 17 vertically connected to the outer tube 10 by a system of rods 18.

[0029] The displacement device of the clamp 2 is positioned on the vertical front face of a frame 3. The displacement device of clamp 12 comprises a first carriage 4 guided along vertical rails 5, and driven along the rails 5 by a motorized assembly (not shown), and a second carriage 6 carried by the first carriage 4, guided along horizontal rails 7 extending along axes (y) parallel to the front face of the frame 3, and driven along the rails by a motorized assembly (not shown). The displacement device also includes a gallow 8 rotatably mounted relative to the second carriage 6 about a horizontal axis (x) perpendicular to the front face of the frame 3. The gallow 8 is rotated by a motor assembly (not shown). The tubular clamp 2 is rotatably mounted within the gallow 8 for rotation around a vertical axis (z), by means of a motor 9.

[0030] In addition, the first carriage 4 is equipped with a retractable stand for stiffening the tubular clamp 2. The first carriage comprises a support piece 19 mounted on the end of the two rods 20a of a jack 20 arranged along an axis (x), whose body 20b is secured to the first carriage 4.

[0031] In addition, this support piece 19 comprises a housing 21 of a shape adapted to house the lower end of the tubular clamp 2. In the lower extension of housing 21 is formed a groove 22 intended to house the upper section of the suspended metal element 1 under the tubular clamp 2.

[0032] The thermal quenching treatment device further comprises a heat treatment device and a cooling device of the type described in the European Patent EP 1 405 926, and thus constituted, respectively, of an induction coil 23 and an annular sprinkler ring 26 in which are integrated spray nozzles 27. Displacement devices are provided to simultaneously move the induction coil 23 and the sprinkler ring 26 along the metal element 1 suspended under the tubular clamp 2, from the lower end section of the metal element 1.

[0033] The displacement device comprises, for each of the two elements, that is, the induction coil 23 and the sprinkler ring 26, a multi-axis robot 24, 28 shown schematically in FIG. 1. Each of the multi-axis robots 24, 28 comprise, in a conventional manner, a terminal arm 25, 29 provided with a gripping member for the induction coil 23 and the sprinkler ring 26.

[0034] The thermal quenching treatment device furthermore comprises, as shown diagrammatically in FIG. 3, a third multi-axis unloading robot 30 equipped with a terminal arm 31 equipped with a gripper 32 for gripping the metal element 1 after heat treatment. The treatment device comprises, finally, an air source 33 connected to inject a cold air flow into the upper end section of the metal element 1 during the heat treatment of the metal element 1.

[0035] According to the principles underlying the thermal quenching treatment device of the present invention, and first of all, with a view to its heat treatment, the metal element 1 is suspended under the tubular clamp 2. The heat treatment is then carried out by simultaneously moving the induction coil 23 and the sprinkler ring 26 along the metal element 1 from the lower end section of the metal element 1. Optionally, the simultaneous movement of the induction coil 23 and the sprinkler ring 26 along the metal element 1 may be by combined with displacements in translation along the axis (y) and/or along the axis (z), and/or rotations around the axis (x) and/or the axis (z) of the tubular clamp 2. Such displacement is intended to allow the metal element 1 to be held in the operating zone of the two multi-axis robots 24, 28, and/or to avoid interference between the heat treatment and the cooling.

[0036] During this heat treatment, moreover, when the metal element 1 consists of a tubular element, cold air is injected into the upper section of the metal element 1, thus making it possible to evacuate the hot vapors produced in the metal element 1 during its cooling, and thus promoting this cooling step.

[0037] In addition, during this heat treatment, the displacement of the induction coil 23 and, possibly, of the tubular clamp 2 are controlled, as shown in FIG. 5, for the length of the induction coil 23, so that the center of the median transverse plane of the induction coil 23 (that is to say the transverse plane located at half-length of the induction coil 23), is at least substantially coaxial with the neutral fiber Fn of the metal element on the median plane thereof (that is to say the longitudinal axis on either side of the median plane). The trajectory conferred on the induction coil 23 according to this principle 25 makes it possible to guarantee obtaining a minimum distance between the internal face of the induction coil 23 and the intrados and the extrados of the metal element 1, even for very short radii of curvature of the order of 1.5 to 2 times the diameter of the metal element. The simultaneous displacement of the induction coil 23 and the sprinkler ring 26 is further adapted to bring the induction coil 23 and the sprinkler ring 26 to a final position, shown in FIG. 3, in which they extend around the tubular clamp 2. Due to the possibility of bringing the induction coil 23 and the sprinkler ring 26 into such a final position, the end of the metal element 1 clamped in the countersink 16 of the tubular clamp 2, a length of the order of ten millimeters, is not subjected to heat treatment.

[0038] However, this end length is usually intended to undergo machining by forming and therefore does not need to be heat treated, so that the treatment device leads to treat the entire length of the metal element 1 requiring a heat treatment. This final position also allows easy access to the metal element 1, allowing its unloading by means of the unloading robot.