FR3002867A1 - TOOL FOR FORMING A FLANGE AT AN END OF A TUBE - Google Patents

Abstract

The invention relates to a tool adapted to form a flange at one end of a metal tube (2) by a material discharge, the tool comprising: a female part (10) comprising a longitudinal recess (11) in which the tube can be immobilized, one end (3) to crimp of said tube remaining free, • a male portion comprising a support (30) and a tooth (40) extending in the longitudinal direction when the female part and the male part are in contact with each other. opposite, the tooth comprising an active end (41) adapted to penetrate the end to deform (3) of the tube, characterized in that: • in the extension of the active part (41), the tooth (40) ) comprises a body (42) having a section larger than the dimensions of the active end (41) of the tooth, an outer lateral surface of the active end (41) and an outer lateral surface of the body (42) of the tooth being connected by a leave (43), • l a tooth is slidably mounted in a recess (34) of the support (30) along the longitudinal axis between:> an initial position where the fillet (43) forms a guide surface adapted to guide the end of the tube being deformed in the direction of an outer face (31) of the support (30) perpendicular to the longitudinal axis, and> a final position where the fillet (43) forms with a wall of the recess (34) of the male part (30). ) a groove (38) in which the wall of the tube comes to rest. The invention also relates to an installation comprising a tool as described above and also comprising means arranged to drive in translation the male part (30) of the tool relative to the female part (10) of the tool according to the invention. the longitudinal axis so that the tooth (40) of the male part (30) penetrates inside a tube immobilized in the female part (10). Application to the crimping of a plate on a tube.

Description

TECHNICAL FIELD AND STATE OF THE ART The invention relates to a tool for forming a flange at one end of a metal tube by repressing material. The invention finds an advantageous application for press-crimping a plate at one end of a tube. This method of assembly avoids the need for welding, an unacceptable technique especially in the case of pre-painted parts, parts articulated on plastic bearings or parts cured on the surface by a treatment incompatible with welding. This method of assembly is for example used to make bases (also called extensions) for seats for motor vehicles, bases precisely made from pre-painted parts, hardened on the surface by a treatment incompatible with welding and articulated on plastic bearings. Conventionally, to crimp a plate at the end of a tube, the end of the tube is inserted into a perforation of the plate, and then the tube is deformed to form a flange of material on one side of the tube. plate and a bead on the other side of the plate so that the plate is immobilized between the flange and the bead flap of material. The deformation is carried out by compressing the end of the tube, using a tool such as that shown in FIGS. 1a, 1b. A known tool comprises a female part 6 a female part comprising a longitudinal recess in which the tube 2 is immobilized while leaving free an end 3 to crimp of said tube. The tool also comprises a male part comprising a tooth 8 secured to a support 7. The tooth has a shape suitable for being inserted inside the tube. The outer surface of the tooth and the outer surface of the support are connected by a fillet 43 having a radius of curvature R. The tool is used with a press arranged to drive the male part in motion relative to the female part (or the reverse) with sufficient force to cause deformation of the metal tube, until the plate is clamped between the female and male portions. The quality of crimping is measured in terms of its mechanical resistance to deformation, tearing. In particular, the deformation of the end of the tube and the movement of the material must be controlled during the discharge, so as to have a bead and especially a flange forming a ring with the largest possible outer diameter. If the radius of curvature R is small, the end of the tube is deformed by winding on itself (Figure lb); the flange finally obtained has a small outside diameter so that its mechanical strength is low. Conversely, if the radius of curvature R is large, the end of the plate in contact with the tube crushes and reduce the thickness of the wall of the tube in the fold zone (Figure la), so that the mechanical strength the collar is too weak. Thus, the existing tools do not make it possible to produce a flange having a good mechanical strength by pushing back material at the end of a tube. DESCRIPTION OF THE INVENTION The invention proposes a new tool for producing at the end of a tube an annular flange having a large outer diameter and thus having a high mechanical strength. More specifically, the invention proposes a new tool adapted to form a collar at one end of a metal tube (2) by material discharge, new tool comprising: - a female part (10) comprising a longitudinal recess (11) in which the tube can be immobilized, one end (3) to crimp of said tube remaining free, - a male part comprising a support (30) and a tooth (40) extending in the longitudinal direction when the female part and the part male are vis-à-vis, the tooth comprising an active end (41) adapted to penetrate into the end to deform (3) of the tube, the new tool is characterized in that: - in the extension of the active part (41), the tooth (40) comprises a body (42) having a section of dimensions greater than the dimensions of the active end (41) of the tooth, an external lateral surface of the active end (41) and a external lateral surface of the body (42) of the tooth being connected by a fillet (43), - the tooth is slidably mounted in a recess (34) of the support (30) along the longitudinal axis between:> an initial position where the fillet (43) forms a guide surface adapted to guiding the end of the tube being deformed towards an outer face (31) of the support (30) perpendicular to the longitudinal axis, and> a final position where the fillet (43) forms with a wall of the recess (34) of the male part (30) a groove (38) in which the wall of the tube comes to rest. The word fillet is traditionally used to define the more or less rounded connection that exists at the meeting of two flat surfaces. By extension, the word fillet is used here to define the connecting surface between the external lateral surface of the active end of the tooth and the external lateral surface of the body of the tooth, surfaces that are not flat, but for example cylindrical , parallelepipedic, etc. The invention also relates to an installation comprising a tool as described above and also comprising a means of action arranged to drive in translation the male part (30) of the tool relative to the female part (10) of the tool along the longitudinal axis so that the tooth (40) of the male part (30) penetrates inside a tube immobilized in the female part (10). According to one embodiment, the means of action is a press comprising means for immobilizing one of the parts, for example the female part, and means for driving in translation other parts, for example the male part. The installation is used as follows. The tube is first immobilized in the recess of the female part. Then the male part is pressed against the female part. When the tooth comes into contact with the wall of the tube, the tooth is in its initial position. The end of the tube wall deforms gradually relying on the leave and then on the outer face of the support to form a collar; as its deformation, the wall of the tube is pressed more strongly on the leave which causes the tooth in motion; the groove is formed little by little around the body of the tooth; the material expelled from the wall of the tube comes to rest gradually in the groove that fills. Thus, as will be seen better later in the figures, the wall of the tube is no longer thinned at the end of the movement but, on the contrary, at the level of the connection zone between the collar formed and the non-deformed portion of the wall of the tube, a thickness at least equal to the initial thickness of the tube, and this regardless of the radius of the leave. Thus, with the tool and the installation according to the invention, it is possible to choose for the fillet a large radius of curvature to achieve an annular flange of large outer diameter having a good mechanical strength.

The male portion may comprise an elastic return means (37) adapted to maintain or bring the tooth into the initial position. Thus, when the means of action of the installation brings the male part closer to the female part of the tool, the wall of the tube which is deformed causes a deletion of the tooth, that is to say a movement of the tooth from its initial position to its final position, erasure controlled by the restoring force of the elastic return means and, after deformation of the end of the tube, the means of action of the installation discard the male part of the female part of the tool and the elastic return means pushes the tooth towards its initial position. According to a preferred embodiment, the body (42) of the tooth (40) is terminated by a head (44) of larger section than the section of the body (42); the recess (34) of the male part is extended by a cavity (35) in which are housed the head (44) of the tooth (40) and a return spring (37); the spring maintains the head of the tooth bearing against a shoulder (36) of the cavity (35) when the tooth is in the initial position, and the head (44) of the tooth compresses the spring (37) when the tooth is in position. final position. Preferably, the support (30) further comprises a groove (32) extending on the outer face (31) at the periphery of an opening of the recess (34), around the tooth (40), the said groove opening on the outer face (31) and in the recess (34) of the support (30). The throat stops the expansion of the end of the wall of the tube along the outer face of the support, as will be seen better below. This makes it possible to obtain a flange having a perfect outer edge, and to obtain perfect reproducibility of the shape of the flanges obtained on a series of successively deformed tubes. The tool may further include means for holding a localized plate between the female and the male portion of the tool. The position of the plate defines the distance L on which the wall of the tube is deformed to form the flange. Without this plate, the wall of the tube can be deformed to the female part. In addition, the female part (10) may comprise a groove (13) extending on a main face (12) of the female part at the periphery of an opening of the recess (11) of the female part, the said groove (13) opening on the main face (12) and in the recess (11) of the female part. This groove allows a discharge of material to form a bead in addition to the collar as will be seen better below. This groove is necessary if only the realization of a flange is considered. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood, and other features and advantages of the invention will emerge in the light of the following description of examples of implementation of a tool and an installation according to the invention. invention. These examples are given in a non-limiting manner. The description is to be read in conjunction with the accompanying drawings, in which: FIGS. 1a, 1b show tools according to the prior art, at the end of the stroke, 2a to 5a show a tool in different positions, FIGS. Sb show a localized detail in dotted lines in the corresponding Figures 2a to 5a Description of embodiments of the invention An installation according to the invention comprises: - a tool comprising:> a female part 10 comprising a longitudinal recess 11 in which the tube 2 can be immobilized, one end 3 to be deformed of the tube remaining free, and> a male part comprising a support 30 and a tooth 40 extending in the longitudinal direction when the female part and the male part are screwed-to -vis, e work position; the tooth comprises an active end 41 adapted to penetrate into the end of the tube to deform, and - a means of action such as a press (not shown), arranged to drive in translation the male part of the tool relative to the female part of the tool along the longitudinal axis of the tube so that the tooth 40 of the male part penetrates inside the tube immobilized in the female part. In the example shown, the female part 10 comprises a longitudinal recess 11 in which the tube 2 can be positioned, the diameter of the recess 11 is adjusted so that the tube is immobilized radially and the length of the tube is adjusted for the end 3 of the tube protrudes from the female part by a height suitable for forming a flange 5 and a bead 4; the recess 11 opens on a main face 12 of the female part 10; the female part 10 also comprises a groove 13 extending on the main face 12 of the female part at the periphery of the opening of the recess; the groove 13 opens on the main face 12 and in the recess 11.

In the male part, the end 41 of the tooth 40 has an outer section substantially equal to an inner section of the tube 2; the tooth extends from a main face 31 of the male part 30 in the longitudinal direction; in the extension of the active portion 41, the tooth 40 comprises a body 42 having a section larger than the dimensions of the active end 41 of the tooth; the outer lateral surface of the active end 41 and an outer lateral surface of the body 42 of the tooth are connected by a fillet 43 having a curvature R.

The tooth 40 is slidably mounted in a recess 34 of the support 30 along the longitudinal axis between:> an initial position (FIGS. 2a, 2b) where the fillet 43 forms a guide surface adapted to guide the end of the tube being deformation towards an outer face 31 of the support 30 perpendicular to the longitudinal axis, and> a final position (FIGS. 5a, 5b) where the fillet 43 forms with a wall of the recess 34 of the male part 30 a groove 38 in which the wall of the tube comes to rest. The body 42 of the tooth 40 is terminated by a head 44 of larger section than the section of the body 42; the recess 34 of the male part is extended by a cavity 35 in which are housed the head 44 of the tooth 40 and a return spring 37; the spring maintains the head of the tooth bearing against a shoulder 36 of the cavity 35 when the tooth is in the initial position, and the head 44 of the tooth compresses the spring 37 when the tooth is in the final position. In the example shown, the tube 2 has a circular section, as well as the active end 41. Also, the body and the head of the tooth 40 have a circular section. However, a body 42 and / or a head 44 having a different section, for example a square section may be considered. In the example shown, the support 30 comprises a groove 32 extending on the outer face 31 at the periphery of an opening of the recess 34, around the tooth 40, said groove opening on the outer face 31 and in the recess 34 of the support 30. Also provided (but not shown) means for holding a crimping plate located between the female part and the male part of the tool.

Finally, the female part 10 comprises a groove 13 extending on a main face 12 of the female part at the periphery of an opening of the recess 11 of the female part, said groove 13 opening on the main face 12 and in the recess 11 of the female part. The installation is used as follows. The tube 2 is positioned inside the recess 11 of the female part 10 and the crimping plate 1 is positioned on the end 3 of the tube (FIG. 2). Then the two parts 10, 30 are brought closer to each other and the material constituting the tube is deformed little by little, in the following manner. In a first step (FIG. 3), the tooth being in its initial position, the edge of the wall of the tube flares out, guided along the fillet 43 until reaching the outer wall 33 of the groove 32, the flange 4 begins to form. In a second step, the tooth 40 begins to sink into the male part (FIG. 4), the wall of the tube bends in a radial fold direction on the side of the female part 10 to form the bead 5, and in parallel the wall of the tube creases in a substantially longitudinal fold direction to fill the groove 38; a rib is formed in the groove 38, which rib will firstly immobilize the repoussé metal and thus facilitate the end of the formation of the collar 4 and the bead 5, and secondly to reinforce the thickness of material at the level of the crimped zone (FIG. 5) and thus strengthen the mechanical strength of the crimping.

Claims (9)

REVENDICATIONS1. Tool adapted to form a flange at one end of a metal tube (2) by material discharge, the tool comprising: - a female part (10) comprising a longitudinal recess (11) in which the tube can be immobilized, an end ( 3) to crimp of said tube remaining free, - a male part comprising a support (30) and a tooth (40) extending in the longitudinal direction when the female part and the male part are in facing relation, the tooth comprising an active end (41) adapted to penetrate the end to be deformed (3) of the tube, characterized in that: - in the extension of the active part (41), the tooth (40) comprises a body ( 42) having a section of dimensions greater than the dimensions of the active end (41) of the tooth, an outer lateral surface of the active end (41) and an outer lateral surface of the body (42) of the tooth being connected by a leave (43), - the tooth is slidably mounted in a recess (34) of the support (30) along the longitudinal axis between:> an initial position where the fillet (43) forms a guide surface adapted to guide the end of the tube being deformed in the direction of a outer face (31) of the support (30) perpendicular to the longitudinal axis, and> a final position where the fillet (43) forms with a wall of the recess (34) of the male part (30) a groove (38). ) in which the wall of the tube comes to rest. 2. Tool according to claim 1 wherein the male part comprises an elastic return means (37) adapted to maintain or bring the tooth into the initial position. 3. Tool according to claim 2 wherein the body (42) of the tooth (40) is terminated by a head (44) of larger section than the section of the body (42), wherein the recess (34) of the male part is extended by a cavity (35) in which are housed the head (44) of the tooth (40) and a return spring (37), the spring holding the head of the tooth in abutment against a shoulder ( 36) of the cavity (35) when the tooth is in the initial position, and the head (44) of the tooth compressing the spring (37) when the tooth is in the end position. 4. Tool according to one of claims 1 to 3 wherein the support (30) comprises a groove (32) extending on the outer face (31) at the periphery of an opening of the recess (34), around the tooth (40), said groove opening on the outer face (31) and in the recess (34) of the support (30). 5. Tool according to one of the preceding claims, further comprising means for holding a crimping plate located between the female part and the male part of the tool. 6. Tool according to one of the preceding claims wherein the female part (10) comprises a groove (13) extending on a main face (12) of the female part at the periphery of an opening of the recess ( 11) of the female part, said groove (13) opening on the main face (12) and in the recess (11) of the female part. 7. Installation comprising a tool according to one of the preceding claims and also comprising a means arranged to drive in translation the male part (30) of the tool relative to the female part (10) of the tool along the longitudinal axis so that the tooth (40) of the male part (30) penetrates inside a tube immobilized in the female part (10). 8. Installation according to claim 7 wherein the drive means is arranged to drive in translation the male part relative to the female part with a force greater than a restoring force of the elastic means of the male part of the tool. 9. Installation according to one of claims 7 or 8 wherein the drive means is arranged to drive in translation the male part relative to the female part until the plate is clamped between the male part and the part female.