Numerically controlled machine tool for machining micromechanical parts from blanks in form of rods or belts

Abstract

Numerically controlled machine tool for machining micromechanical parts from blanks in the form of rods or belts. The utility model relates to a numerical control machine tool (10) used for machining micromechanical parts from blanks (100) in the form of a strip, the machine tool comprises a frame (12), a part loader unit (11) used for keeping the parts (100) in proper positions and a tool loader unit (13) used for bearing cutting tools (130), the part loader unit (11) is kinematically connected to the frame (12), and the tool loader unit (13) is used for bearing the cutting tools (130). The tool carrier unit (13) is kinematically connected to the frame (12) so as to have only one rotational degree of freedom and one translational degree of freedom in the direction Z in a reference frame XYZ with respect to the frame (12), and the tool carrier unit (13) is kinematically connected to the frame (12) so as to have only one translational degree of freedom in the direction X and one rotational and translational degree of freedom in the direction Y with respect to the frame (12).

Description

Technical Field

[0001] The utility model belongs to the field of numerical control machine tools, and in particular relates to a numerical control machine tool for machining micro-mechanical parts from a blank in the form of a bar or a band.

[0002] In this context, the term "rod" is intended to mean any solid or hollow wire, profile or tube, regardless of its cross-sectional shape. Background Art

[0003] In the field of micromechanics, reducing the size of CNC machine tools and especially reducing the size of the machine tools relative to the machining volume brings many advantages, including increased cutting and cutting tool movement speed due to the reduced inertia of the moving mass parts, a reduction in the floor space required for storing the machine tools, and a reduction in the energy consumption of such machine tools.

[0004] However, reducing the size of a machine tool may be accompanied by a loss of its static rigidity, that is to say the parts forming the machine tool are more susceptible to deformation, which is disadvantageous for the high-precision machining required by micro-technological applications such as watchmaking.

[0005] In the field of mechanics, the concept of "machine tool stiffness" characterizes the dimensional stability of the parts forming the machine tool under the influence of thermal gradients or mechanical stresses, in particular the parts forming the kinematic path between the part to be machined and the cutting tool passing through the part forming the machine tool, that is to say the force loop. Utility Model Content

[0006] The present invention overcomes the above-mentioned disadvantages and for this purpose relates to a CNC machine tool for machining micromechanical parts from blanks in the form of rods or strips, the machine tool comprising a frame, a part carrier unit for holding the parts in an appropriate position, and a tool carrier unit for carrying a cutting tool.

[0007] As used herein, the term "cutting tool" refers to any tool used to remove material from a part, whether fixed (such as a turning tool) or rotating (such as a milling tool).

[0008] The part carrier unit is kinematically connected to the frame so as to have, in the reference system XYZ, one rotational and translational degree of freedom relative to the frame in the direction Z. The tool carrier unit is kinematically connected to the frame so that it has only one translational degree of freedom in the direction X and one rotational and translational degree of freedom in the direction Y relative to the frame.

[0009] In this document, the term "direction" refers to an axis extending in a given direction. For example, direction X refers to axis X or an axis parallel to axis X.

[0010] Advantageously, the invention allows optimizing the ratio between the dimensions of the machine tool and the dimensions of the blank and more particularly allows minimizing the dimensions of the machine tool and / or maximizing the dimensions of the blank.

[0011] As an example, the machine tool is designed so that the volume of the machine tool is substantially five times the volume of the processing zone, and the volume of the blank before processing is at least five times the volume of the processing zone. Therefore, the ratio between the volume of the machine tool and the volume of the blank can be equal to one.

[0012] In certain embodiments, the present invention may further include one or more of the following features alone or in any technically possible combination.

[0013] In a particular embodiment, the part carrier unit comprises a part carrier carriage connected to the frame by at least one slide fixed directly to the frame, the part carrier carriage comprising a part carrier module adapted to be controlled to be in a clamped state or in a released state, in which the part carrier module holds the part in position and in which the part carrier module allows the part to be moved.

[0014] In a particular embodiment, the part carrier carriage has a through opening which extends in the direction Z and opens at one of its ends at the part carrier module, said opening being used to receive parts for supplying the machining area of ​​the machine tool.

[0015] In a particular embodiment, the tool carrier unit comprises a first carriage connected to the frame by at least one slide fixed directly to the frame and extending in direction X. The tool carrier unit comprises a second carriage connected to the first carriage and comprising a tool carrier that can be moved rotationally and translationally in direction Y.

[0016] In a particular embodiment, the second carriage is mounted on at least one slide fixed to the first carriage and extending in the direction Y, the tool carrier being rotationally movable relative to the second carriage.

[0017] In a particular embodiment, the machine tool comprises an additional unit kinematically connected to the frame so as to have only one rotational and translational degree of freedom in direction Z. The additional unit is arranged such that the cutting tool is placed between the part carrier unit and said additional unit, said additional unit comprising an additional carriage arranged opposite the part carrier unit and receiving a part counter-carrier module for fixing or releasing the part, or receiving a second tool carrier for carrying the cutting tool.

[0018] In a particular embodiment, the additional carriage has a through opening extending in the direction Z and opening at one of its ends at the part carrier module opposite, for receiving the part in order to remove it from the machining area of ​​the machine tool.

[0019] In a particular embodiment, the additional carriage is mounted on at least one slide fixed to the frame, the slide to which the parts carrier carriage and the additional carriage are connected being formed by the same slide.

[0020] In a particular embodiment, both the part carrier module and the part counter-carrier module can include positioning means for guiding the parts as they are moved, or for holding the parts in position.

[0021] In a particular embodiment, the machine tool comprises a second tool carrier unit similar to the tool carrier unit, which is arranged symmetrically to the tool carrier unit with respect to the symmetry plane YZ so that the tool carrier unit is located on either side of the part carrier unit and the additional unit, respectively. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Other features and advantages of the invention will become apparent from the following detailed description, which is given by way of non-limiting example with reference to the accompanying drawings, in which:

[0023] - Figure 1 A perspective view showing a variation of the machine tool according to a preferred embodiment of the utility model, in which the blank to be machined is in the form of a rod;

[0024] - Figure 2 Shows Figure 1 A perspective view of another variant of the machine tool, in which the blank to be machined is in the form of a strip;

[0025] - Figure 3 Shows Figure 1 Front view of the machine tool;

[0026] - Figure 4 Shows Figure 3 Detail of the machine tool in a cross-sectional view along the axis AA.

[0027] It should be noted that for the sake of clarity, the drawings are not necessarily drawn to scale. DETAILED DESCRIPTION

[0028] The numerically controlled machine tool 10 according to the utility model is suitable for processing blanks (such as Figure 1 In the form of a rod, or as shown in Figure 2In a manner known to those skilled in the art, the machine tool 10 includes a monitoring and control unit, such as a microcontroller, for receiving instructions in the form of a computer program and controlling the components of the machine tool 10 according to these instructions. Since driving the various components of the machine tool 10 is within the capabilities of those skilled in the art and is not per se the subject of the present invention, these aspects are not discussed in greater detail herein.

[0029] In a preferred application of the invention, the machine 10 is suitable for obtaining parts dedicated to the watchmaking sector, in particular buttons, crowns, screws, shafts, pinions, etc., when the blank is in the form of a rod; and bridges, plates, clutch levers (bascule), centerpieces, balance wheels, wristband links, etc., when the blank is in the form of a belt. The blank is moved so as to be fed into the machining area of ​​the machine 10 so as to machine the parts one by one from said blank. In order to simplify the reading of this document, the blank and the part being machined or already machined are referred to by the same term "part" 100.

[0030] As shown in the figure, the machine tool 10 comprises a part carrier unit 11, which is used in particular to hold the part 100 in position during machining. The part carrier unit 11 is kinematically connected to a frame 12 so as to have only one rotational degree of freedom in the direction Z and one translational degree of freedom in the orthogonal reference system XYZ. Figures 1 to 3 As illustrated in , the part carrier unit 11 is configured to hold the part 100 in a position such that the part 100 extends longitudinally in the direction Z. This feature allows limiting the inertia of the moving element when the part carrier unit 11 is moved.

[0031] The rotational freedom of the part carrier unit 11 advantageously enables it to be driven in order to perform a turning operation on the part 100, or in order to perform a milling operation in different angular positions of the part 100. As an example, the part carrier unit 11 can be configured to drive the part 100 at a speed of up to 8000 rpm or more, for example up to 20000 rpm, during a turning operation. It goes without saying that the turning operation is only applicable to a part 100 in the form of a rod.

[0032] In the present invention, the frame 12 is formed by rigid structural elements of the machine tool 10. Due to the features of the present invention, the frame 12 can be relatively compact, as shown in the figures.

[0033] The machine tool 10 further comprises a tool carrier unit 13 for carrying a cutting tool 130 and which is kinematically connected to the frame 12 so as to have only one translational degree of freedom in the X direction, one rotational degree of freedom in the Y direction and one translational degree of freedom.

[0034] The machine tool 10 thus comprises five degrees of mobility, three of which are dedicated to the tool carrier unit 13 and two of which are dedicated to the part 100. Therefore, the majority of the movements are performed by the component with the lowest mass, that is to say by the tool carrier unit 13. Furthermore, from a kinematic point of view, an attempt is made to limit the number of translational degrees of freedom of the tool carrier unit 13 to two, in order to limit the total mass of the active elements and therefore to minimize the stresses related to inertia, in order to be able to use relatively compact connection elements, as described in more detail below.

[0035] Overall, these arrangements also allow minimizing the number of connections placed between the tool carrier unit 13 and the part carrier unit 11 respectively and the frame 12 , which has the advantage of allowing a rigid structure of the machine tool 10 while minimizing its volume and mass.

[0036] In particular, the component carrier unit 11 comprises a component carrier carriage 110 mounted on at least one slide 120 fixed directly to the frame 12. The component carrier carriage 110 comprises a component carrier module 112, for example composed of Figure 1 and Figure 3 The chuck shown in or Figure 2 100 is formed by the positioning device shown in . In a known manner, the part carrier module 112 is suitable for being driven in a clamped state, in which it holds the part 100 in place, or in a released state, in which it allows the part 100 to move. The part carrier carriage 110 has a through opening extending in the direction Z, through which the part 100 is intended to be guided in order to be fed into the machining area of ​​the machine tool 10. It is understood here that the opening opens at one of its ends, which is located at the part carrier module 112.

[0037] Furthermore, the tool carrier unit 13 comprises a first carriage 131 mounted on at least one slide 120 fixed directly to the frame 12 and extending in the direction X. The tool carrier unit 13 also comprises a second carriage 133 mounted on at least one slide 120 fixed to the first carriage 131 and extending in the direction Y. The second carriage 133 comprises Figures 1 to 4 The tool carrier 135 shown in FIG. 1 is rotationally movable about a direction Y (such as a tool carrier spindle).

[0038] like Figure 1 and Figure 2As shown in , direction X is oriented vertically (that is, in the direction of gravity). Therefore, the first carriage 131 may be subjected to greater forces than the second carriage 133, because these forces are related to the mass of the elements supported by the first carriage 131 and the second carriage 133, respectively. The first carriage 131 is also configured to travel farther than the second carriage 133, in particular to remove the cutting tool 130 from the processing area.

[0039] Since the first slide 131 is directly connected to the frame 12 , the additional force on the first slide 131 and its longer stroke compared to the second slide 133 do not affect the rigidity of the machine tool 10 .

[0040] It is understood here that the arrangement of the degrees of freedom of the part carrier carriage 110 and of the first and second carriages 131 and 133 of the tool carrier unit 13 is particularly advantageous since it allows, on the one hand, minimizing the mass of the moved elements and therefore the stresses to which the machine tool 10 is subjected, and, on the other hand, allowing these stresses to be transmitted as directly as possible to the frame 12. Due to these features, the machine tool 10 and in particular the tool carrier unit 13 and the part carrier unit 11 benefit from excellent dynamic performance, the inertia of the moving elements being suppressed and the rigidity of the machine tool 10 being increased.

[0041] Due to the design of the machine tool 10 according to the invention, the slide 120 can be dimensioned relatively compactly.

[0042] These features also allow protective walls (not shown) to be easily incorporated into the machine tool 10 to protect it from projected material fragments and machining lubricants. These protective walls are arranged so as to form a processing chamber that is substantially sealed from the external environment. In addition, by sealingly fixing the walls to the frame 12 on the one hand and to each carriage on the other hand (for example by means of wipers 121 or bellows 122), the processing chamber can be designed to be very compact.

[0043] In particular, the bellows 122 is Figure 1 1 is schematically shown as transparent in order to show in particular the slide 120 . Figure 3 and Figure 4 An example of a bellows 122 is shown, which bellows comprises two opposite deformable walls, one of which extends and the other retracts depending on the position occupied by the carriage. Figure 4 Also shown is a wiper 121 mounted around the tool carrier 135 , in particular at a cylindrical portion of the tool carrier 135 extending in the direction Y.

[0044] It should be noted that when the machine tool 10 is used to perform a milling operation, the tool carrier 135 is configured to rotate the cutting tool 130 (that is, the milling cutter) about its longitudinal axis. This arrangement can be implemented by commercial solutions available to those skilled in the art. As an example, when performing a milling operation, the tool carrier 135 can be configured to rotate the cutting tool 130 about its longitudinal axis at more than 60,000 rpm (for example, at 70,000 rpm).

[0045] The machine tool 10 may comprise an additional unit 14 which is kinematically connected to the frame 12 so as to have only one degree of freedom in translation and one degree of freedom in rotation in the direction Z. Figure 1 and Figure 2 As shown, the additional unit 14 comprises an additional carriage 140 mounted on at least one slide 120 fixed directly to the frame 12. The additional unit 14 is arranged so as to be arranged on either side of the tool carrier unit 13 together with the part carrier unit 11. In other words, the cutting tool 130 is placed between the part carrier unit 11 and the additional unit 14.

[0046] Advantageously, the slide 120 to which the component carrier carriage 110 and the additional carriage 140 are connected can be formed by the same slide. Advantageously, this feature ensures alignment between the component carrier carriage 110 and the additional carriage 140.

[0047] The additional carriage 140 is adapted to receive a part counter-carrier module 141 or a second tool carrier (not shown) arranged opposite to the part carrier unit 11. When the additional carriage 140 comprises the part counter-carrier module 141, the additional carriage 140 is used to hold the part 100 in a suitable position, and when the additional carriage 140 comprises the second tool carrier, the additional carriage 140 is used to process the part 100 held by the part carrier module 112 by milling or drilling.

[0048] In particular, the part carrier module 141 may be provided by a fixture or a mandrel (eg, Figure 1 ) or an assembly device (as shown in Figure 2 ) is formed in the same manner as described above.

[0049] Like the part carrier carriage 110 , the additional carriage 140 has a through opening 142 which extends in the direction Z and opens at one of its ends at the part counter-carrier module 141 . The part 100 is intended to be guided through the through opening 142 in order to be removed from the machining area of ​​the machine tool 10 .

[0050] Advantageously, in Figure 1In the example shown in , the part counter-carrier module 141 can be controlled to grip the part 100 held by the part carrier carriage 110, in particular by the part carrier module 112, so that the part is only immobilized in the appropriate position by the part counter-carrier module 141 after being released by the part carrier module 112, so that a new processing phase can be performed. During this new processing phase, the cutting tool 130 can then access the following areas of the part 100: These areas were not accessible when the part was held in the appropriate position by the part carrier module 112, and the processing of the part 100 can therefore be completed.

[0051] In addition, Figure 2 In the example shown in , the part 100 (in this case a strip) can advantageously be held simultaneously by the part carrier module 112 and the part counter-carrier module 141. Such positioning devices are also used, for example, in combination with part carrier positioning devices to guide the part 100 when the part 100 is moved. To this end, the positioning device comprises a guide rail with which the part 100 cooperates and a clamping device suitable for fixing or releasing the part 100.

[0052] In this exemplary embodiment of the invention, the part carrier module 112 and the part counter-carrier module 141 can be controlled so as to move the part 100 in a feed motion, that is to say, the part 100 is translated in only one orientation in the direction Z. This feed motion of the part 100 is performed, for example, before a machining phase and at the end of a machining phase, to produce an inflow of the part 100 in the form of the original part and an outflow of the part 100 in the form of the machined part 100 of the machine tool 10. More specifically, in order to move the part 100 in this feed motion, for example, the part carrier module 112 or the part counter-carrier module 141 is driven so as to hold the part 100, while the other module is driven to release the part 100, whereupon the module holding the part is translated in a given orientation in the direction Z. The module is then driven so as to release the part 100, while the other module is driven to hold the part.

[0053] During the machining phase, the part carrier module 112 and the part counter-carrier module 141 can also be driven to move the part 100. More specifically, in this case, both the part carrier module 112 and the part counter-carrier module 141 are driven with the same translation movement and possibly rotation movement (to tilt the part 100 in the direction Z), in particular when the part 100 is in the form of a rod.

[0054] When the additional carriage 140 receives the second tool carrier, the second tool carrier is adapted to carry a cutting tool, such as a milling tool or a turning tool, so that the second device 14 allows turning and milling operations to be performed on a part secured by the tool carrier module 112 .

[0055] like Figure 1 and Figure 2 As shown in FIG. 1 , in a preferred embodiment of the present invention, the part carrier slide 110 , the first slide 131 , the second slide 133 and the additional slide 140 are supported by two slides 120 .

[0056] Advantageously, the machine tool can be considered to comprise a second tool carrier unit similar to the tool carrier unit 13, which is arranged symmetrically to the tool carrier unit 13 with respect to the symmetry plane YZ, so that said tool carrier unit is located on either side of the part carrier unit 11 and the additional unit 14, respectively. The advantage of this feature is that it allows simultaneous machining operations on parts held in position by the part carrier unit 11 and the additional unit 14. The second tool carrier unit is similar to the tool carrier unit 13, in that it also has a tool carrier unit for carrying a cutting tool and is kinematically connected to the frame 12 with the same degrees of freedom as the tool carrier unit 13.

[0057] More generally, it should be noted that the above embodiments and examples have been described by way of non-limiting examples and that other variations are therefore possible.

[0058] In particular, Figure 1 and Figure 2 The exemplary embodiment shown in and described above relates to a machine tool 10 which is supplied by guiding parts 100 through a machining zone. However, the machine tool 10 according to the invention may be adapted to machine parts 100 in batches, such as small pieces, the supply of which is performed sequentially, each machined part 100 coming from a different blank 100.

[0059] The second tool carrier may also carry a fixed or rotating tailstock.

[0060] It should be noted that the translational and rotational movements of the part carrier unit 11 and the tool carrier unit 13 and any additional units 14 are ensured in a manner known to a person skilled in the art by independent electric motors servo-controlled by a monitoring and control unit.

Claims

1. A numerically controlled machine tool (10) for machining micromechanical parts from blanks in the form of rods or strips, the machine tool comprising a frame (12), a part carrier unit (11) for holding the part (100) in position, and a tool carrier unit (13) for carrying a cutting tool (130), characterized in that: - the part carrier unit (11) is kinematically connected to the frame (12) so as to have one degree of rotational freedom and one degree of translational freedom in direction Z relative to the frame (12) in a reference system XYZ, The tool carrier unit (13) is kinematically connected to the frame (12) so as to have only one degree of freedom in translation in the X direction and one degree of freedom in rotation and translation in the Y direction relative to the frame (12).

2. The machine tool (10) according to claim 1, wherein: The part carrier unit (11) comprises a part carrier slide (110), which is connected to the frame (12) by at least one slide (120), and the part carrier slide (110) comprises a part carrier module (112), which is suitable for being controlled to be in a clamping state or in a released state, in which the part carrier module holds the part (100) in an appropriate position, and in which the part carrier module allows the part (100) to be moved.

3. The machine tool (10) according to claim 2, wherein: The part carrier carriage (110) has a through opening which extends in the direction Z and opens at one of its ends at the part carrier module (112) for receiving the part (100) for supplying a machining area of ​​the machine tool (10).

4. The machine tool (10) according to any one of claims 1 to 3, wherein: The tool carrier unit (13) comprises a first slide (131) and a second slide (133), the first slide being connected to the frame (12) via at least one slide (120) extending in the direction X, the second slide being connected to the first slide (131) and comprising a tool carrier (135) capable of rotational and translational movement in the direction Y.

5. The machine tool (10) according to claim 4, wherein: The second slide (133) is mounted on at least one sliding member (120), which is fixed to the first slide (131) and extends in the direction Y.

6. The machine tool (10) according to any one of claims 1 to 3, wherein: The machine tool comprises an additional unit (14), which is kinematically connected to the frame (12) so as to have only one rotational degree of freedom and one translational degree of freedom in the direction Z, the additional unit (14) being arranged so that the cutting tool (130) is placed between the part carrier unit (11) and the additional unit (14), and the additional unit comprises an additional slide (140) arranged opposite to the part carrier unit (11) and receiving a part counter-carrier module (141) for fixing or releasing the part (100), or receiving a second tool carrier for carrying the cutting tool (130).

7. The machine tool (10) according to claim 6, wherein: The additional carriage (140) has a through opening (142), which extends in the direction Z and opens at one of its ends located at the part opposite carrier module (141), and the through opening (142) is used to receive the part (100) so as to remove it from the processing area of ​​the machine tool (10).

8. The machine tool (10) according to claim 6, wherein: The additional carriage (140) is mounted on at least one slide (120) fixed to the frame (12), the parts carrier carriage (110) and the slide (120) to which the additional carriage (140) is connected being formed by the same slide.

9. The machine tool (10) according to claim 2, wherein: Both the part carrier module (112) and the part counter-carrier module (141) can include positioning means for guiding the part (100) when it is moved, or for holding the part (100) in place.

10. The machine tool (10) according to claim 6, wherein: The machine tool comprises a second tool carrier unit similar to the tool carrier unit (13), which is arranged symmetrically to the tool carrier unit (13) relative to the symmetry plane YZ, so that the tool carrier unit is located on either side of the part carrier unit (11) and the additional unit (14), respectively.

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