Clock installation.

Abstract

One aspect of the invention relates to a fixture (20) for holding a flat component (1), comprising radial support stops, and a chamber bordered by jaws (21; 22) having locking surfaces for holding the component (1), open on one side by a clearance to perform an operation on the component (1), this fixture (20) is deformable between an open position and a closed position around the component (1) held by said jaws (21; 22) subjected to a closing force exerted by operating means arranged to bring these jaws (21; 22) closer together.

Description

Technical field of the invention

[0001] The invention relates to a fixture for holding in machining and / or assembly position a substantially flat component of thickness less than or equal to a predetermined maximum thickness and extending on either side of a median plane.

[0002] The invention further relates to a means of production comprising a machining and / or assembly device carrying such a fixture

[0003] The invention relates to the field of manufacturing tools for micromechanics, in particular for watchmaking. Technological background

[0004] In the prior art, with regard to the production of watch blanks, the referencing of the component to be machined is ensured by pins (positioning side) which fit into holes (workpiece side). This requires, during the loading and unloading of the parts, a vertical insertion movement along the axis of the pins. The component is held by point supports using fairly large blank holders, which are movable clamps that bear locally on certain surfaces of the component and are capable of inducing deformation of the component in the event of excessive pressure.

[0005] To allow this vertical insertion, the blank holders must be disengaged. This is often achieved by rotating each of the rotaryly mounted blank holders 90°. This rotation is generated by a cam coupled to the vertical movement of the blank holders. Thus, the vertical movement of the blank holders is relatively large, as it combines two distinct movements: a vertical clamping movement and a combined vertical rotary movement to rotate the blank holders.

[0006] This large stroke makes the use of flexible joint technology impossible, due to the limited strokes inherent in this type of technology. These state-of-the-art fixtures therefore cannot be monolithic; they are often composed of many parts that slide within one another, giving them a certain amount of play and thus necessarily reducing rigidity and precision. The large strokes, the large number of parts, and the operations required for assembly make these fixtures relatively bulky, complex, heavy, and expensive. The creation of multiple fixtures on the same pallet or support is, consequently, hampered by the same considerations.

[0007] This also results in very limited access for machining; often only one face is accessible, and even then, only in a restricted way. Therefore, for machining on both sides, it is necessary to disassemble the component, turn it over, and perform a new positioning and clamping operation prior to machining the other face. Summary of the invention

[0008] The invention aims to develop a fixture to improve the machining accuracy of components, through a simpler, single-step process.

[0009] Prior art fixtures are often bulky, heavy, complex and expensive.

[0010] The invention further implements a one-piece fixture, which makes it possible to improve the performance of the fixture (rigidity, precision), to reduce complexity and weight, making it more suitable for fulfilling the conditions for very high speed machining (VHSM) and / or for miniaturization in the trend of micromachines / “microfactories”.

[0011] For this purpose, the invention relates to a fixture for holding in machining and / or assembly position a substantially flat component of thickness less than or equal to a predetermined maximum thickness and extending on either side of a median plane, according to claim 1.

[0012] The invention further relates to a means of production comprising a machining and / or assembly device carrying such a fixture and such a driver to control a movement of the fixture between its opening and closing positions, according to claim 18. Brief description of the figures

[0013] The objects, advantages and features of the invention will become clearer in the following detailed description, with reference to the accompanying drawings, where: Figure 1 represents, schematically and in plan view, the usual centering of a blank by pins, in micromechanics, this blank being held frontally by clamps called blank holders, not shown here, and which encroach significantly on the machining area; Figure 2 represents, similarly to Figure 1, the positioning method specific to the implementation of the invention, with radial support of the blank on stops located outside the machining area; some front and radial machining operations to be performed are shown on this blank; Figure 3 represents, schematically and in perspective, a fixture according to the invention, comprising two jaws, one of which is intended to be fixed on a machine, and the other of which is movable relative to the first;An infeed slot between these jaws allows the introduction of a blank up to the stops illustrated in Figure 2, not visible here; flexible joints with elastic blades can be seen on the sides of the fixture, forming a parallel table system between the two jaws, and whose small size allows for large clearances for machining: in the example illustrated above and below, and on the sides; Figure 4 represents, similarly to Figure 3 and from another angle, the same fixture; Figure 5 represents, similarly to Figure 3 and from yet another angle, the same fixture, from the side of the fixing base on one of the jaws; Figure 6 represents, schematically and in section, the fixture of Figures 3 to 5, in a variant which includes retaining inserts between the jaws and the blank; the jaw fixed to the machine is in the lower part, the upper jaw is movable parallel to the previous one;Grooves incorporating stop surfaces ensure stroke limitation; Figure 7 schematically represents, in top view, from the upper jaw side, the mounting of Figures 3 to 6; Figure 8 schematically represents, in side view, the mounting of Figures 3 to 7; the upper jaw is at the bottom of the figure; Figure 9 schematically represents, in bottom view, from the lower jaw side, the mounting of Figures 3 to 8; Figure 10 schematically represents, in side view, the mounting of Figures 3 to 9; the lower jaw is at the bottom of the figure; Figure 11 schematically represents, in cross-section, the blank and its maximum thickness; Figure 12 schematically represents a detail of a flexible joint;Figure 13 schematically represents a production means comprising a machining and / or assembly device carrying such a fixture and such a driver to control a movement of the fixture between its opening and closing positions; the driver is here carried by one of the jaws; Figure 14 represents, similarly to Figure 13, such a production means where the driver is carried by the machining and / or assembly device. Detailed description of the invention

[0014] The invention relates to a machining and / or assembly fixture for flat / thin parts (such as watch blanks), allowing access to all faces of such a component. In the remainder of this description, the term "fixing" will be used to define the device according to the invention, designed for holding a component during a machining and / or assembly operation. "Machining" here refers broadly to any operation performed on a component, including, but not limited to, machining with cutting tools, lasers, water jets, plasma cutting, or similar processes, as well as heat or surface treatment, screen printing, painting, or other processes; "assembly" similarly refers to any operation involving joining components, such as pressing, riveting, brazing, welding, gluing, or other processes.

[0015] The invention is designed mainly for substantially flat components 1 (also called flats), of a thickness less than or equal to a predetermined maximum thickness E and extending on either side of a median plane (PM); the rough of such a component 1 is not necessarily symmetrical, and may include protruding or re-entrant reliefs, as seen in Figure 11, provided that the maximum thickness dimension E is respected, like a coin to be inserted into a coin slot.

[0016] More particularly, in a particularly advantageous embodiment, this fixture is a single piece with flexible joints.

[0017] Figures 1 and 2 highlight the difference between the prior art and the invention.

[0018] Figure 1 illustrates the vertical insertion of a component onto two pins, in the usual prior art. This is a conventional clamping method, with component 1 inserted vertically. In this conventional method, pins are inserted vertically (perpendicular to the drawing plane) into holes, or vice versa. To allow the insertion of component 1 onto its fixture, several blank holders (often four) distributed across the component's surface must move upwards and pivot to provide access for positioning component 1, and then for removing it at the end of the operation. This generally implies a clamping stroke of several millimeters or even centimeters for the blank holders, as the rotation of the blank holders is achieved via a cam that converts the vertical movement into rotation (typically 90°).

[0019] Figure 2 illustrates the locking method proposed during implementation of the invention, with component 1 inserted horizontally until it reaches a stop support. This type of insertion requires a specific type of fixture 20, which is the subject of the invention.

[0020] According to the invention, this fixture 20 comprises stops 2, 3, which define at least two radial stop support surfaces S1, S2, S3, comprising generatrices substantially perpendicular to a reference plane PR of the fixture 20, and which are arranged to cooperate in stop support with peripheral edge support surfaces 11, 12, 13, of a component 1.

[0021] Of course, the chosen clamping method depends on the type of roughing prior to the operation, and on any peripheral machining that may be carried out during a cutting, stamping, or machining operation, before the operation to be performed on the fixture 20: it is quite clear that the number, shape, and position of the contact surfaces depend on this particular roughing geometry. For example, component 1 may have two surfaces defining a V-shape, working in conjunction with two complementary stop surfaces defining a complementary V-shape.The non-limiting variant illustrated in Figure 2 concerns a three-point isostatic referencing system, allowing horizontal insertion in the plane of the figure: a first stop 2 bears against a first notch in component 1, which has two surfaces 11 and 12, against which two radial stop bearing surfaces S1 and S2 bear; a second stop 3 bears against a recess in component 1, which has a flat surface 13, against which a radial stop bearing surface S3 bears. In a particular and non-limiting manner, and as seen in the illustrated embodiment, these radial notches can be obtained either by stamping or by pre-machining component 1.

[0022] The fixture 20 is arranged so that the median plane PM of a component 1 comes parallel or coincides with the reference plane PR, in the machining and / or assembly position.

[0023] Thanks to the horizontal insertion, the clamping stroke, which is carried out on the thickness of component 1, can be very small, on the order of a few tenths of a millimeter, and this can be advantageously achieved with flexible joints.

[0024] According to the invention, the fixture 20 comprises a chamber 40 which is bordered, on either side of the reference plane PR, by jaws 21 and 22, which have locking surfaces 310, 320, for holding a component 1. Advantageously, these locking surfaces 310, 320 are substantially annular, so as to distribute the clamping force well on the component 1, and to prevent any harmful deformation.

[0025] The chamber 40 is open, on at least one side of the reference plane PR, by at least one clearance 41, 42, 43; This clearance 41, 42, or 43 is suitable for allowing the passage of a tool, another component, or a machining and / or assembly means to perform an operation on a component 1. Advantageously, the fixture 20 has two clearances 41 and 42, one on each side, on either side of the reference plane PR. It is thus possible to perform operations on the front and back of the same component 1, for example, but not limited to, front machining operations 108 such as those visible in Figure 2, in a single clamping operation, simply by controlling a rotation of the fixture 20. The embodiment illustrated in the figures also includes lateral clearances 43, which have the advantage of allowing machining on the edge of the component 1, such as the machining operation 109 in Figure 2, for example, the housing of a control rod or a pusher on a watch plate.

[0026] The fixture 20 has a single insertion hole 30, which is suitable for allowing the insertion of a component 1 into the chamber 40 towards the radial abutment support surfaces S1, S2, S3, of the fixture 20, in a single direction.

[0027] The fixture 20 is deformable between, on the one hand, an open position and on the other hand, a closed position. The figures illustrate a non-limiting embodiment in which each of the jaws 21, 22, has a reference surface 35, 34 respectively, parallel to the reference plane PR of the fixture 20, and, in a preferred kinematic, these two reference surfaces 35 and 34 remain parallel to each other during the closing and opening maneuvers.

[0028] In the open position, the insertion orifice 30 has a maximum opening width equal to the predetermined maximum thickness E, in the direction of the thickness of a component 1 on either side of its median plane PM. In this open position, a component 1 can be inserted into the chamber 40 until it rests against the radial abutment bearing surfaces S1, S2, S3.

[0029] In the closed position, the fixture 20 is deformed around a component 1 held in contact with the radial bearing surfaces of the stop S1, S2, S3, and clamped over its thickness by the jaws 21, 22, subjected to a closing force exerted by operating means arranged to bring the jaws 21, 22 closer together.

[0030] In the advantageous example illustrated, one of the jaws 21 is movable relative to the other jaw 22, which is fixed to the production means. Of course, each of the jaws can also be movable relative to a fixed structure, but this increases the cost of the mechanism and its size.

[0031] Advantageously, the movement from the open position to the closed position tends to reinforce the support of component 1 on its stop supports.

[0032] In one embodiment, at least one of the jaws 21, 22 comprises friction means which are arranged to tend to drive a component 1 in abutment support on the radial abutment support surfaces S1, S2, S3, during the closing maneuver.

[0033] The fixture 20 includes means for printing a relative biased stroke of the jaws 21 and 22 with respect to each other, while maintaining parallelism between the reference surfaces 35 and 34.

[0034] It is understood that the design of the fixture 20 allows for the gripping and clamping of components 1 of different morphologies, provided that their thickness is less than the maximum thickness E, and that their retention by the clamping surfaces 310, 320 remains possible; in this regard, the figures illustrate a particular embodiment in which the clamping surfaces 310, 320 are part of removable inserts 31 and 32 which together define the insertion orifice 30. Naturally, the fixture 20 can also include clamping surfaces 310, 320 directly at the jaws 21, 22. The use of removable inserts 31, 32 provides versatility to the fixture, allows for the handling of different dimensions and geometries of blanks, and also allows for good maintenance with the guarantee of always clean contact surfaces. However, Posage 20 is designed to work even without such inserts.

[0035] The mounting 20 can be achieved in different ways, including with a classic, but costly, articulated fabrication.

[0036] In the spirit of simultaneous machining of a plurality of components, for example in a set on a pallet, it is advantageous to reduce as much as possible the manufacturing cost of such fixtures, which can then be dedicated to a family of components.

[0037] Figures 3 to 10 illustrate an advantageous, non-limiting embodiment in which, with the exception of the removable inserts shown above, the fixture 20 is monobloc.

[0038] Figure 3 illustrates such a monobloc fixture 20, which can be fixed directly onto a pallet, onto the axes of a machine tool, or similar.

[0039] More particularly, the operating means include flexible joints 200 provided in the fixture 20, and which are arranged to generate, by elastic deformation, a relative movement between the jaws 21, 22. Here the upper jaw 21 is held to the lower jaw 22 only by its flexible joints 200, and a groove 25 separates it from the base 29 which is included in the lower jaw 22, and which serves to fix the fixture 20 to the machine.

[0040] More particularly, each flexible joint 200 includes a chamber 26, cut both in the upper jaw 21 and in the lower jaw 22, in which chamber 26 is movable a lever mass 23, which is attached to each of the jaws 21, 22 by an elastic blade 24 or by a collar, to form with the other flexible joints 200 a parallel table, so as to control the parallel relative displacement of the reference surfaces 35 and 34.

[0041] This fixture 20 thus comprises flexible joints 200, which are machined from this part. These flexible joints 200 are designed to generate, by elastic deformation, a relative movement between the upper and lower parts of the clamping, which constitute the jaws 21 and 22. In this particular embodiment, each flexible joint comprises a chamber 26, machined in both the upper jaw 21 and the lower jaw 22, in which a lever mass 23 is movable, which is attached to each of the jaws 21 and 22 by an elastic blade 24; in a variant not shown, each elastic blade 24 can be replaced by a collar; this design explains the small stroke of the jaws 21 and 22 relative to each other, but in return it guarantees perfect repeatability of the kinematics, and good durability.This configuration is known as a "parallel table", also used in mechanical watch oscillators.

[0042] For the protection of the elastic blades 24, the fixture 20 advantageously includes at least one stroke-limiting device 28, represented by a groove in the shape of a capital S in the figures, and whose opposing surfaces 281 and 282 cooperate as stop supports at the end of the useful stroke of the jaws 21 and 22, to prevent any dangerous deformation of the flexible joints 200, and in particular of the elastic blades 24, outside their normal working range. Thus, the force loop passes through the stops, and not through the blades. It is understood that the technology of parallel tables with thin elastic blades, produced by a "LIGA" or similar process, ensures perfectly parallel movement, but over a very small stroke, which is perfectly compatible with the clamping function provided by the fixture according to the invention.The safety features provided by the stroke limiter device 28, as well as by the faces of the groove 25 which constitute an additional safety support for the end-of-stroke stop, are therefore essential for good durability and repeatability of performance.

[0043] More particularly, one of the jaws 21, 22, is an upper jaw 21 driven by a driver 100 which is internal to the fixture 20 or external to the fixture 20, and which includes the operating means, and the other of the jaws 21, 22, is a lower jaw 22 including a base 29 arranged for fixing the fixture 20 to a machining and / or assembly device 300 within a production means 1000.

[0044] In a first variant, the trainer 100 is internal to the bearing 20 and fixed to the base 29, as seen in figure 13.

[0045] In a second variant, the driver is external to the fixture 20 and fixed to a machining and / or assembly device on which the fixture 20 is fixed, as seen in Figure 14.

[0046] The upper jaw 21 can be actuated by a driver 100 such as a piston or similar.

[0047] In one variant, each lever 23 is oblique but not perpendicular to the reference plane PR.

[0048] In another variant, each lever 23 is oblique but passes through a position perpendicular to the reference plane PR, in its stroke between its opening position and its closing position.

[0049] The rest angle of the levers 23 (not limited to four in the figures) can be optimized according to the application. The closer the levers 23 are to the vertical (i.e., to the perpendicular to the reference plane PR), the greater the amplification effect of the clamping force. Through horizontal actuation (i.e., parallel to the reference plane PR), a vertical clamping force is obtained, and the component 1 to be machined is pinched between the upper jaw 21 and the lower jaw 22 of the fixture 20.

[0050] Advantageously the fixture 20 comprises a single-piece assembly consisting of the jaws 21, 22 and the flexible joints 200 which connect them to each other and which are arranged to, by elastic deformation under the action of a driver 100 on at least one of them, generate a relative clamping movement between the jaws 21, 22.

[0051] The invention further relates to a production means 1000, comprising at least one machining and / or assembly device 300 carrying at least one such fixture 20 and at least one such driver 100, and further comprising control means for each driver 100 to control a movement of the respective fixture 20 between its opening and closing positions.

[0052] The invention is described herein in an application as a one-way clamping actuator. Naturally, it can also be used to constitute a two-way actuator. In that case, it should be equipped with a force and stroke limiter in each direction of operation.

[0053] In summary, the invention provides an ultra-compact fixture allowing easy access to all faces of component 1, and thus complete machining in a single clamping operation. Machining a part in a single clamping operation has very positive repercussions on the accuracy of component 1, because this arrangement will not accumulate repositioning errors that are always present during repeated machining.

[0054] The fixture according to the invention is simple, made of a single piece, very precise, without backlash or hysteresis, and with perfectly linear behavior. This fixture is also very rigid, being a single piece. Furthermore, the fixture is lightweight, which allows its use for highly dynamic applications such as high-speed turning or milling operations, or other operations requiring little energy or force to be moved according to the movements of the machining center.

[0055] Finally, the development of this fixture is advantageously dimensioned in order to be integrated into a multi-spindle machine.

Claims

1. Fixture (20) for holding in machining and / or assembly position a substantially flat component (1) of thickness less than or equal to a predetermined maximum thickness (E) and extending on either side of a median plane (PM), characterized in that said fixture (20) comprises stops (2; 3) defining at least two radial stop support surfaces (S1; S2; S3) comprising generatrices substantially perpendicular to a reference plane (PR) of said fixture (20), with respect to which reference plane (PR) said median plane (PM) of said component (1) is parallel or coincident in said machining and / or assembly position, and which are arranged to cooperate in stop support with peripheral edge support surfaces (11; 12; 13) of said component (1), and in that said fixture (20) comprises a chamber (40) which is edged, on either side of said reference plane (PR), by jaws (21; 22) comprising locking surfaces (310;320) for holding said component (1), said chamber (40) being open on at least one side by a clearance (41; 42) suitable for allowing the passage of a tool or another component or a machining and / or assembly means to perform an operation on said component (1), in that said fixture (20) has a single insertion hole (30) suitable for allowing the insertion of said component (1) into said chamber (40) towards said radial abutment support surfaces (S1; S2;S3) said fixture (20), and in that said fixture (20) is deformable between an open position in which said insertion orifice (30) has a maximum opening of width equal to said predetermined maximum thickness (E), in the direction of the thickness of said component (1) on either side of its said median plane (PM), and in which open position said component (1) can be inserted into said chamber (40) until it is in a buttress support position on said radial buttress support surfaces (S1; S2; S3), and a closed position around said component (1) held in support on said radial buttress support surfaces (S1; S2; S3) and clamped by said jaws (21; 22) subjected to a closing force exerted by operating means arranged to bring said jaws (21; 22) closer together.; 2. Assembly (20) according to claim 1, characterized in that at least one of said jaws (21; 22) comprises friction means arranged to tend to drive pushing said component (1) in abutment support on said radial abutment support surfaces (S1; S2; S3) during the closing maneuver.

3. Installation (20) according to claim 1 or 2, characterized in that said chamber (40) is open, on at least one side of said reference plane (PR), by a clearance (41; 42) allowing a said component (1).

4. Posing (20) according to claim 3, characterized in that said chamber (40) is open, on each side of said reference plane (PR), by a clearance (41; 42) allowing access to said component (1) from both sides.

5. Installation (20) according to claim 3 or 4, characterized in that said chamber (40) is opened by at least one clearance (43) allowing lateral access to an edge of said component (1).

6. Fixture (20) according to any one of claims 1 to 5, characterized in that one of said jaws (21; 22) is an upper jaw (21) driven by a driver (100) which is internal to said fixture (20) or external to said fixture (20) and which comprises said operating means, and in that the other of said jaws (21; 22) is a lower jaw (22) comprising a base (29) arranged for fixing said fixture (20) to a machining and / or assembly device.

7. Posement (20) according to claim 6, characterized in that said driver (100) is internal to said posement (20) and fixed to said sole (29).

8. Fixture (20) according to claim 6, characterized in that said driver (100) is external to said fixture (20) and fixed to a machining and / or assembly device (300) on which said fixture (20) is fixed.

9. Fixing (20) according to any one of claims 1 to 8, characterized in that said operating means comprise flexible joints (200) provided in said fixing (20), which are arranged to, by elastic deformation, generate a relative movement between said jaws (21, 22).

10. Assembly (20) according to claims 6 and 9, characterized in that each said flexible joint (200) comprises a chamber (26), cut both in said upper jaw (21) and in said lower jaw (22), in which chamber (26) is movable a lever mass (23), which is attached to each of said jaws (21, 22) by an elastic blade (24) or by a collar, to form with the other said flexible joints (200) a parallel table.

11. Posing (20) according to claim 10, characterized in that each said lever (23) is oblique but not perpendicular with respect to said reference plane (PR).

12. Posement (20) according to claim 10, characterized in that each said lever (23) is arranged to pass through a position perpendicular to said reference plane (PR), in its stroke between its opening position and its closing position.

13. Fixture (20) according to any one of claims 9 to 12, characterized in that said fixture (20) comprises at least one stroke limiting device (28) comprising antagonistic surfaces (281; 282) which are arranged to cooperate in support of the stop at the end of the useful stroke of said jaws (21; 22), to avoid any dangerous deformation of said flexible joints (200) outside their normal working range.

14. Mounting (20) according to claim 13, characterized in that said mounting comprises, between said jaws (21; 22) a groove (25) the faces of which constitute an additional safety support for the end stop.

15. Fixing (20) according to any one of claims 1 to 14, characterized in that said locking surfaces (310; 320) are part of said jaws (21; 22).

16. Mounting (20) according to any one of claims 1 to 14, characterized in that said locking surfaces (310; 320) are part of removable inserts (31; 32) housed in said jaws (21; 22), and which together define said insertion orifice (30).

17. Fixing (20) according to any one of claims 1 to 16, characterized in that said fixing (20) comprises a single-piece assembly consisting of said jaws (21; 22) and flexible joints (200) which connect them to each other and which are arranged to, by elastic deformation under the action of a driver (100) on one of them, generate a relative clamping movement between said jaws (21, 22).

18. Production means (1000), comprising at least one machining and / or assembly device (300) carrying at least one fixture (20) according to claim 6 and one of claims 1 to 17, and at least one said driver (100), and further comprising control means for each said driver (100) to control a movement of said respective fixture (20) between its opening and closing positions.