EP3055104B1 - Device with small vertical bulk for clamping a part on a tool - Google Patents

Description

FIELD OF THE INVENTION

The invention relates to a device with a small vertical space for clamping a workpiece on a tool, of the type comprising a jack and a flange actuated by the jack. Such devices according to the preamble of claim 1 are for example known documents DE 4007590 A1 , US 3,724,837 A , US 3,565,415 A , EP 0 663 268 A1 , DE 195 31 889 A1 and FR2 743 320 A1 .

PRIOR ART

It is common to make machining tools for the manufacture of parts by removal of material. Such tools are designed to be quickly put in place on a machine tool such as a machining center. They comprise keys for receiving and positioning one or more workpieces. They further include clamping devices to hold the workpiece in place during the machining phase.

The document FR 2 743 320 A1 shows an example of a clamping device operated by a fluid such as a hydraulic fluid or air. The device comprises a jack and a flange, the flange being actuated by the jack via transmission means. The flange moves in an arcuate housing, so that the flange moves in a pivoting motion. A clamping surface at the end of the flange is intended to come into contact with the workpiece to be clamped so as to clamp the workpiece. The device is intended to be fixed on the tooling.

Such a device effectively maintains the parts, and is of limited size relative to the plane of attachment of the device, thanks to the orientation of the axis of the cylinder substantially parallel to the plane of attachment. However, the movement of berthing of the piece is made in a curved path and mainly oblique with respect to the support plane of the part. This results in a possible sliding of the piece on its supports and a variable positioning from one room to another.

OBJECTIVES OF THE INVENTION

The aim of the invention is to provide a clamping device with reduced overall dimensions with respect to a fastening plane and ensuring tightness and reliable positioning in the direction of the fastening plane.

STATEMENT OF THE INVENTION

With these objectives in view, the invention relates to a device for clamping a workpiece on a tool, comprising a jack and a flange, the flange being actuated by the jack via transmission means, the jack being selectively actuated by a fluid under pressure and itself comprising a body fixed in operation to the tooling by a fixing face, and a slide slidably mounted relative to the body along a slide axis substantially parallel to the attachment face, the flange struggling under the action of the cylinder between a clamping position and a release position in which it is recessed relative to the clamping position. The device is characterized in that it further comprises guide members provided for driving the flange in a movement comprising a rotation about a pivot axis at least at the end of its stroke towards its release position and following a translational movement in a clamping direction oblique or perpendicular to the axis of the slider and perpendicular to the pivot axis at least at the end of its stroke towards its clamping position.

The device according to the invention can be put in place with the slide axis parallel to an attachment plane, which makes it possible to obtain a clamping movement perpendicular to the plane of attachment. As the clamping movement is straight, no sliding movement on the supports is induced for the workpiece to be clamped. This provides a high reliability of the attachment, while having a limited space above the attachment plane, due to the orientation of the cylinder.

According to a particular arrangement, the guide members comprise first guiding means and second guiding means spaced apart from each other so as to define the path of the flange between the clamping position and the releasing position. The guiding means make it possible to define both the position of the flange and the orientation thereof.

In particular, the first and second guide means respectively comprise a first and a second finger cooperating respectively with a first and a second cam. The cooperation of a finger and a cam makes it possible to define the trajectory of a point of the flange in a plane. By combining two sets of this type, the path of the flange is completely defined.

According to a particular arrangement, the first finger is mounted on the flange while the first cam is carried by the body.

In a complementary manner, the first cam comprises a first portion in which the first finger is located when the flange is in the clamping position, the first portion being parallel to the clamping direction, and a second portion which is oriented towards the jack. In combination with the second guide means, the first portion corresponds to the rectilinear movement towards the clamping position. The orientation of the second portion provides a tilting of the flange, so as to clear the space above the room and facilitate its introduction or removal.

According to another arrangement, the second finger is mounted on the body while the second cam is carried by the flange extending rectilinearly and in the clamping direction when the flange is in the clamping position. This arrangement allows the rectilinear movement of the flange to the clamping position.

According to a constructive arrangement, the transmission means comprise a transmission pin and a transmission cam cooperating with each other. These means make it possible to transform the rectilinear motion of the slider into a movement combining a phase of rotation and a phase of translation in another direction.

In particular, the slide has a flat foot, the transmission cam being carried by the foot of the slide, the flange having a flange groove in which the foot extends and slides, the transmission cam being traversed by a pin forming the transmission finger. The flange groove guides the slider to ensure the permanent orientation of the transmission cam. The movement of the slider conditions the movement of the pin which drives the flange. This ensures the transformation of the sliding movement provided by the cylinder. In addition, the pin is not oriented in the cam so that pivoting of the flange about the axis of the pin is allowed.

According to a particular embodiment, the transmission cam comprises a first portion inclined with respect to the axis of the slide, and a second portion substantially perpendicular to the axis of the slide and in which the transmission finger is located when the flange is in position of looseness. When the transmission finger engages in the second portion, in the movement towards the release position, the driving of the flange is carried out substantially in the direction of sliding, which facilitates the tilting of the flange and decreases the stroke of the jack for tilting.

According to a constructive arrangement, the body comprises a yoke, the yoke having two wings parallel to each other, the flange struggling between the wings. This can lead to a solid and balanced guide of the flange. In addition, the wings protect the flange, especially against intrusions of chips or dust.

The device comprises first support elements and second support elements, the first support elements comprising a first support element fixed relative to the body and a first movable support element connected to the flange, the first fixed and movable support members cooperating selectively, at least at the end of the stroke of the flange towards its clamping position, to mutually offer a sliding contact parallel to the tightening direction, the second bearing elements comprising a second support element fixed relative to the body and a second movable support element connected to the flange, these second fixed and movable support elements cooperating selectively, at least at the end of the stroke of the flange towards its position of clamping, to afford each other a sliding contact parallel to the clamping direction, the first and second support members being spaced apart from each other to allow a bridging of the flange on the part. e to tighten. Thus, the clamping forces are transmitted between the body and the flange by direct contact between surfaces of each of these parts, which ensures good rigidity of the clamping, without biasing the guide means.

According to a constructive arrangement, the first fixed support element is constituted by a bearing surface of the body between the wings of the yoke, the first movable support element being constituted by a first heel of the bridle.

According to another constructive arrangement, the second movable support element is constituted by two second bearing heels carried by the flange and extending symmetrically on either side of a median plane of the flange and the slide, transverse to the pivot axis, and the second fixed support element is constituted by two body bearing grooves formed in the wings facing each other, on the sides of which the second support heels 'support symmetrically with respect to said median plane. The second support element is thus placed between the wings of the yoke and are well protected against chips and dust.

According to an improvement, the slide is made by a rod and a piston joined by assembly, the rod being connected to the transmission means. It is thus possible to impart a substantial dimension to the transmission means, without being limited to the diameter of the rod. Indeed, by a two-piece design, we can introduce the rod on one side of the bore that guides the rod and bring the piston on the other side. The assembly is carried out for example by screwing the piston on the rod.

According to a particular arrangement, the body comprises a fixing face substantially perpendicular to the clamping direction. This provides means for fixing the device on a tool attachment plane and to apply a clamping force in the direction of the attachment plane.

BRIEF DESCRIPTION OF THE FIGURES

• la figure 1 est une vue en perspective d'un dispositif de serrage conforme à un mode de réalisation de l'invention et en position de relâchement ;
• la figure 2 est une vue en perspective du dispositif de la figure 1 selon un autre angle de vue et en position de serrage ;
• la figure 3 est une vue en coupe selon un plan médian du dispositif en position de relâchement ;
• la figure 4 est une vue similaire à la figure 3, en position de serrage ;
• la figure 5 est une vue similaire à la figure 3, en position intermédiaire entre la position de relâchement et la position de serrage ;
• la figure 6 est une vue en perspective du dispositif de la figure 1, un cache latéral étant supprimé ;
• la figure 7 est une vue de dessus du dispositif de la figure 1.

The invention will be better understood and other features and advantages will appear on reading the description which follows, the description referring to the appended drawings among which:

• the figure 1 is a perspective view of a clamping device according to an embodiment of the invention and in the release position;
• the figure 2 is a perspective view of the device of the figure 1 according to another angle of view and in the clamping position;
• the figure 3 is a sectional view along a median plane of the device in the release position;
• the figure 4 is a view similar to the figure 3 , in the clamping position;
• the figure 5 is a view similar to the figure 3 in an intermediate position between the release position and the clamping position;
• the figure 6 is a perspective view of the device of the figure 1 , a side cache being deleted;
• the figure 7 is a top view of the device of the figure 1 .

DETAILED DESCRIPTION

A clamping device according to the invention is shown on the Figures 1 to 7 . It comprises a body 1 forming the body of a jack 2 and a flange 3 operated by the jack 2. It comprises a fixing face 10 intended to bear fixedly on the fastening plane F of a tooling 0, and four through holes perpendicular to the attachment face 10 and for receiving fixing screws. In the remainder of the description, mention will be made of the top and the bottom with reference to the position of the device on the tooling 0 on the fastening plane F, considering that the fixing plane F is free horizontal upwards. However, it goes without saying that the device can take any other orientation.

The body 1 has a general rectangular parallelepipedal shape and comprises a yoke 11 whose two flanges 110 extend perpendicularly to the attachment face 10 in a symmetrical manner relative to a plane perpendicular to the attachment face 10. The flange 3 is struggling between the flanges 110 of the yoke 11 between a clamping position and a releasing position, being guided between the inner faces of the wings 110 to move parallel to the plane of the wings 110. The flange 3 has a spout 30 which protrudes from the body 1 beyond a front face 11 when in the clamping position, so as to extend beyond above the fastening plane F of the tooling 0 and to tighten a part to be clamped P in the direction of the fastening plane F. In the release position, as shown in FIG. figures 1 and 3 , the spout 30 of the flange 3 has receded so as to be substantially aligned with the front face 11, ie recessed relative to the clamping position. The flange 3 protrudes slightly above the body 1, that is to say opposite the fixing face 10.

The jack 2 comprises a slider 20 slidably mounted in a bore 21 of the body 1 extending along a slider axis A parallel to the attachment face 10. The slider 20 comprises a piston 201 and a rod connected to the piston 201 by screwing. The bore 21 is closed by a cover 21 so as to define a first chamber 23 in the bore 21 between the piston 201 and the stopper. A second chamber 24 is also delimited in the bore 21 by the piston 201, on the opposite side to the first chamber 23. Each chamber 23, 24 is in fluid communication with a first orifice 101 and a second orifice 102 opening on the face respectively. 10. Thus, a connection with supply ducts can be carried out on the fastening plane F. Seals are provided in the appropriate places that are not detailed here.

The rod 202 passes through a neck 25 which connects the second chamber 24 and the space between the wings 110 of the yoke 11. In this space, the rod 202 joins the flange 3 by means of transmission means 4. The transmission means 4 comprise a substantially flat foot 40 carried by the rod 202, a flange groove 41 carried by the flange 3 in which the foot 40 is adjusted so as to be slidably mounted in a plane parallel to the axis of slide A 20 and perpendicular to the attachment face 10 and a transmission pin formed by a pin 42 passing through the flange 3 perpendicular to said plane. The foot 40 comprises a transmission cam 401 which passes through it and which extends in a first portion 4011 obliquely with respect to the axis of slide A and a second portion 4012 perpendicular to the axis of slide A, the extreme side of the pin 202 opposite the piston 201. The pin 42 passes through the transmission cam 401. It is introduced through a mounting hole 43 formed in one of the flanges 110 opposite the position of the pin 42 when the flange 3 is in the tightening position. The mounting hole 43 is closed by a plug 44 placed after the passage of the pin 42.

The clamping device further comprises guide members 5 provided for driving the flange 3 along a predefined path. The path comprises a rotation about a pivot axis at least at the end of its stroke towards its release position. This pivoting is therefore performed along a pivot axis perpendicular to the plane of the wings 110. The trajectory further comprises a translational movement in a clamping direction perpendicular to the axis of the slider 20 at least at the end of its stroke towards its position. Clamping. This translation is therefore also perpendicular to the pivot axis. For this, the guide members 5 comprise first guide means 51 and second guide means 52, spaced apart from each other, so as to define the path of the flange 3 between the clamping position and the position of looseness.

The first guide means 51 comprise a first finger 511 cooperating with a first cam 512. The first finger 511 is mounted on the flange 3 while the first cam 512 is carried by the body 1. The first cam 512 is composed of two grooves first cam 5120 formed in the wings 110 symmetrically and through the wings 110. The first finger 511 is formed of two pins 5110 screwed on either side of the flange 3, so as to be housed in the grooves of first cam 5120. The first cam 512 comprises a first portion 5121 in which the first finger 511 is located when the flange 3 is in the clamping position, and which is parallel to a clamping direction S perpendicular to the attachment face 10, and a second portion 5122 which moves away from the front face 11.

The second guide means 52 are placed closer to the attachment face 10 than the first guide means 51 and comprise a second finger 521 cooperating with a second cam 522. The second finger 521 is mounted on the body 1 while the second Cam 522 is carried by the flange 3 extending rectilinearly and in the tightening direction S when the flange 3 is in the clamping position. The first finger 511 is substantially in alignment with the second cam 522. The second cam 522 is composed of two grooves of second cam extending on either side of the flange 3. The second finger 521 is composed of two pins 5210 passing through the flanges 110 of the yoke 11 and projecting towards the flange 3 by being housed in the grooves of the second cam 522.

The clamping device further comprises first bearing elements 6 comprising a first fixed support element 61 with respect to the body 1 and a first movable support element 62 connected to the flange 3, these first fixed and movable support elements 61, 62 cooperating selectively, at the end of the stroke of the flange 3 towards its clamping position, to offer each other a sliding contact parallel to the clamping direction S. The first element of fixed support is constituted by a bearing surface 61 of the body 1 between the flanges 110 of the yoke 11, perpendicular to the attachment face 10, and the first movable support member is constituted by a first bead 62 of the flange 3 located on the furthest part of the fixing face 10.

The clamping device further comprises second support elements 7 comprising a second fixed support element 71 relative to the body 1 and a second movable support element 72 connected to the flange 3. The second movable support element 72 is constituted by two second bearing heels 721 carried by the flange 3 and extending symmetrically on either side of a median plane M of the flange 3 and the slider 20, transverse to the pivot axis. The second fixed support element 71 is constituted by two bearing grooves 711 of the body 1 made in the wings 110, one facing the other, on the sides of which the second support heels 721 are based symmetrically with respect to said median plane and can slide in a direction perpendicular to the attachment face 10. The bearing grooves 711 are open on the attachment face 10. They also have clearances so that the second bearing heels 721 can rotate as the flange 3 pivots to the release position.

Thus, the first and second support elements 6, 7 are spaced from each other and allow a bracing of the flange 3 on the part to be clamped P.

The clamping device also comprises two lateral covers 8, housed in a recess 80 provided on the outer faces of the wings 110 and covering the grooves of the first cam 512. The covers 8 are fixed by the second finger pins 5210 which are screwed into the wings 110. They also cover the passage hole 43 and the plug 44 which is inserted therein.

A front cover 9 is also fixed on the front face 11 of the body 1, in a rabbet 90 provided for this purpose on the end of each of the wings 110. The front cover 9 extends from the attachment face 10 to half-height of the body 1, so as to leave a small gap between the front cover 9 and the flange 3 when the flange 3 passes from the clamping position to the release position.

Operation of the clamping device

It is assumed that initially the flange 3 is in the release position, as shown on the figures 1 and 3 . In this position, the piston 201 is as close to the cover 21 and the slide 20 is in the retracted position. The pin 42 is in the second transmission cam portion 4012 401. The first finger 511 is in the second portion 5122 of the first cam 512, while the second finger 521 is at the end of the second cam 522 opposed to the side of the spout 30. The flange 3 is inclined so that the first bead 62 passes over the body 1.

By sending a pressurized fluid into the first chamber 23, and allowing that contained in the second chamber 24 to exit, the slide 20 is controlled to slide to an extended position. The foot 40 of the slider 20 pushes on the pin 42 engaged in the second portion 4012 of the transmission cam 401 so as to cause the sliding of the first finger 511 in the second portion 5122 of the first cam 512. The flange 3 then makes a pivoting movement about the axis of the second finger 521. The flange 3 also begins to slide at the second level finger 521 in the groove of second cam 522. During this pivoting, the spout 30 protrudes more significantly beyond the front face 11.

When the first finger 511 engages in the first portion 5121 of the first cam 512, the pin 42 engages the oblique portion 4011 of the transmission cam 401. The flange 3 is then in a vertical position, as shown on the figure 5 . The displacement of the flange 3 is then a translational movement perpendicular to the attachment face 10. This movement is controlled by the sliding of the pin 42 in the oblique portion 4011 of the transmission cam 401, until the spout The clamping force is thus provided by the jack 2, and is converted into a vertical force by the transmission cam 401. During the translational movement, the first bead 62 engages in look at the bearing surface 61 sliding against it. Furthermore, the second support heels 721 slide in the bearing grooves 711. The clamping position is then reached.

The return to the release position is obtained by reversing the fluid supply of the chambers 23, 24 of the cylinder 2. This gives a movement in the opposite direction to that just described.

The invention is not limited to the embodiment which has just been described by way of example. The slider axis A is not necessarily parallel to the attachment face 10, but it can be plunging. The transmission cam 401 could be rectilinear, at the cost of a slightly larger stroke of the slider 20. The second cam and the second finger 521 could be respectively fixed and movable. The clamping direction could be oblique with respect to the attachment face, in order to adapt to oblique tightening directions relative to the attachment plane of the tooling.

Claims (15)

1. Device for clamping a part to be clamped (P) on a tool (0), comprising a jack (2) and a flange (3), the flange (3) being actuated by the jack (2) via transmission means (4), the jack (2) being selectively actuated by a pressurised fluid and itself comprising a body (1) fixed to the tool (0) during operation by a fastening face (10), and a slide (20) slidably mounted relative to the body (1) along a slide axis (A) substantially parallel to the fastening face (10), the flange (3) travels under the action of the jack between a clamping position and a release position wherein it is retracted relative to the clamping position, the device being characterised in that it further comprises guiding members (5) provided to drive the flange (3) following a movement comprising a rotation around a pivot axis at least at the end of its travel toward its release position and following a translational movement in a clamping direction (S) oblique or perpendicular to the axis of the slide (A) and perpendicular to the pivot axis at least at the end of its travel toward its clamping position.
2. Device for clamping according to claim 1, characterised in that the guiding members (5) comprise first guiding means (51) and second guiding means (52), separated from one another, in such a way as to define the trajectory of the flange (3) between the clamping position and the release position.
3. Device for clamping according to claim 2, wherein the first and the second guiding means (51, 52) comprise respectively a first and a second finger (511, 521) cooperating respectively with a first and a second cam (512, 522) .
4. Device for clamping according to claim 3, wherein the first finger (511) is mounted on the flange (3) while the first cam (512) is carried by the body (1) .
5. Device for clamping according to claim 4, wherein the first cam (512) comprises a first portion (5121) wherein the first finger (511) is located when the flange (3) is in the clamping position, and which is parallel to the clamping direction (S), and a second portion (5122) which is oriented towards the jack (2).
6. Device for clamping according to claim 3, wherein the second finger (521) is mounted on the body (1) while the second cam (522) is carried by the flange (3) by extending in a straight manner and in the clamping direction (S) when the flange (3) is in the clamping position.
7. Device for clamping according to claim 1, wherein the transmission means (4) comprise a transmission finger (42) and a transmission cam (401) cooperating between them.
8. Device for clamping according to claim 7, wherein the slide (20) comprises a foot (40) with a flat shape, the transmission cam (401) being carried by the foot (40) of the slide (20), the flange (3) comprising a flange (3) groove wherein the foot (40) extends and slides, the transmission cam (401) being passed through by a pin (42) forming the transmission finger (42).
9. Device for clamping according to claim 7, wherein the transmission cam (401) comprises a first portion (4011) inclined relative to the axis of the slide (A), and a second portion (4012) substantially perpendicular to the axis of the slide (A) and wherein the transmission finger (42) is located when the flange (3) is in the release position.
10. Device for clamping according to claim 1, wherein the body (1) comprises a cheek (11), the cheek comprising two wings (110) parallel between them, the flange (3) travelling between the wings (110).
11. Device for clamping according to claim 1, characterised in that it comprises first supporting elements (6) and second supporting elements (7), the first supporting elements (6) comprising a first fixed supporting element (61) relative to the body (1) and a first movable supporting element (62) connected to the flange (3), these first fixed and movable supporting elements (61, 62) cooperating selectively, at least at the end of the travel of the flange (3) towards its clamping position, in order to mutually be provided with a sliding contact parallel to the clamping direction (S), the second supporting elements (7) comprising a second fixed supporting element (71) relative to the body (1) and a second movable supporting element (72) connected to the flange (3), these second fixed and movable supporting elements (71, 72) cooperating selectively, at least at the end of the travel of the flange (3) towards its clamping position, in order to mutually be provided with a sliding contact parallel to the clamping direction (S), the first and second supporting elements (6, 7) being at a distance from one another in order to allow for a bracing of the flange (3) on the part to be clamped (P).
12. Device for clamping according to claims 10 and 11 taken in combination, wherein the first fixed supporting element is comprised of a support surface (61) of the body (1) between the wings (110) of the cheek (11), the first movable supporting element being comprised by a first talon (62) of the flange (3).
13. Device for clamping according to claims 10 and 11 taken in combination, wherein the second movable supporting element (72) is comprised of two second support heels (721) carried by the flange (3) and extending symmetrically on either side of a median plane (M) of the flange (3) and of the slide (20), transversal to the pivot axis, and the second fixed supporting element (71) is comprised of two support grooves (711) of the body (1) made in the wings (110) one opposite the other, on flanks of which the second support heels (721) symmetrically bear against relative to said median plane.
14. Device for clamping according to claim 1, wherein the slide (20) is carried out by a rod (202) and a piston (201) made integral via assembly, the rod (202) being connected to the transmission means (4).
15. Device for clamping according to one of the preceding claims, wherein the body comprises a fastening face substantially perpendicular to the clamping direction.

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