WO1989011373A1 - Machining unit comprising at least one assembly movable on a support member - Google Patents

Abstract

The invention relates to a machining unit movable along one or a plurality of translation or rotation axes and which is provided with manual driving means to control said motions. Said machining unit is arranged to be fitted with ditigal control driving means (38, 39) replacing at least part of the driving means. To this effect, the machining unit is particularly provided with housings (35, 37) for mounting ditigal control members (34, 38, 40, 41), for example for a translation motion by means of a screw (13) and a ball nut (12). A particular housing (35) is provided for the mounting of a ditigal rotation sensor (34) at one end of the screw.

Description

 MACHINING UNIT COMPRISING AT LEAST ONE MOBILE ASSEMBLY ON A SUPPORTING MEMBER.

The present invention relates to a convertible machining unit from a manual control to a digital control comprising at least one mobile assembly mounted on a support member so as to be mobile according to at least one degree of freedom, and manual means for drive to move and position the mobile assembly relative to the support member.

Machining units of this kind generally comprise 1, 2 or 3 mobile assemblies mounted one on top of the other, so that the last assembly, provided with a rotary spindle actuating a machining head, is respectively movable along 1, 2 or 3 degrees of freedom, which can correspond to translational or rotational movements depending on the case. Increasingly, these units are standardized and are arranged to receive different tools in order to increase their versatility. One or more of these units can be mounted on the same machine, in order to machine parts simultaneously or successively by the different units.

The control members of known machining units are either of the manual type or of the numerically controlled type. Numerical control involves relatively large investments from the point of view of the acquisition of hardware and software, as well as the training of personnel, so that certain workshops are nevertheless equipped with machining units with controls. manual if these are sufficient for their needs. However, the day when increased needs will require switching to numerical control, these machining units will have to be replaced by new units, better suited to the new requirements.

German patent application No. 2 2> 0. 01 1 describes a machine tool having manual screw controls to which a removable digital control device can be connected to carry out, before work, a pre-adjustment of the machine, in particular for placing limit stops. A similar device is also presented in German patent application No. 2 326 369. However, none of these devices does not allow to transform a machine with manual control in machine working in numerical control.

For its part, British patent application No. 62Ψ 263 shows a machine tool having a sliding unit normally displaced by a screw mechanism, but arranged to be coupled to an external motorized drive by means of a flexible transmission. . This does not make the machine ^'in NC.

To solve the problem mentioned above, the present invention aims to provide a machining unit in which at least part of the manual control means can be easily converted to digital control.

To this end, the invention provides a machining unit of the type indicated in the preamble, characterized in that the manual drive means are at least partially demountable, and in that the machining unit is provided with reserved housings to receive at least one position sensor and numerical control drive means replacing at least part of said manual drive means.

In a particular embodiment, said manual drive means comprise at least one control screw rotatably mounted and engaged in an element that is threaded or toothed, and the machining unit comprises, near this screw. at least one housing for a digital sensor coupled to this screw and a housing for a motorized drive member of the screw. Preferably, the housing for a digital sensor extends in the extension of one end of the screw. The motorized drive member can be coupled to the other end of the screw.

In the case where the manual drive means comprise a crank device which is coupled to said screw, an advantageous solution is that this crank arrangement is removable.

In general, manual means of training can be completely removable to be replaced by the numerically controlled drive means.

In one embodiment of the machining unit according to the invention, the movable assembly comprises a machining head which is movable along at least three degrees of freedom, and the machining unit is arranged for be equipped with numerically controlled drive means according to each degree of freedom. In particular, the machining head can be movable in translation along three axes, respectively by means of three control screws. A respective housing for a digital rotation sensor can be reserved near each of the three control screws.

The present inventi on and its advantages will appear better in the description below of an exemplary embodiment, with reference to the appended drawings, in which:.

Figure 1 is a general perspective view of a machining unit arranged according to the present invention.

FIG. 2 is a side elevation view, partially cut away, showing manually controlled drive members fitted to this machining unit, and

FIG. 3 is a view analogous to FIG. 2 and shows drive members with numerical control installed in the same machining unit, in the region of the lustrous members in f igure 2.

With reference to the figures, the machining unit shown is designed to be equipped, as desired, with manually controlled or numerically controlled drive members, and in particular in such a way that it is possible to replace easily. the first of these organs by the second. Manually controlled members appear only in FIG. 2, while numerically controlled members are provided in the version illustrated by FIGS. 1 and 3. The machining unit is of the triaxial movement type, along three orthogonal translation axes. In known manner, it comprises a support 1 arranged to be fixed to the frame 2 of a machine, a first carriage 3 mounted on the support 1 and movable in translation along a vertical axis, this carriage carrying at its upper part a pair of slides oriented along a second axis which is horizontal, a second carriage 5 mounted on the slides. by means of preloaded ball pads' to be movable in translation along the second axis, and a third carriage 6 movable on horizontal slides (not shown) of the second carriage, said slides being perpendicular to the slides •. to define a third axis of translation which is parallel to the axis of rotation of the spindle 7. The carriage 6 is equipped with a rotary spindle 7 intended for carrying tools, as well as a motor 8 for the drive of spindle.

The device shown and described for a spindle with a horizontal axis of course also applies to a spindle with a vertical axis.

In the version illustrated more particularly by FIG. 2, the respective movements of translation of the first carriage 3 and of the second carriage 5 are carried out manually. For this purpose, the support I com carries a part 1 1 carrying a trapezoidal thread nut 1 2 in which is engaged a screw 1 3 whose lower end 1 is rotatably mounted in the first carriage 3 by means of a ball bearing 15. The other end of the screw 13 is coupled, by means of a bevel gear with bevel gears 16 and 17, to a manual control shaft IS also mounted in the carriage 3 and provided with an outer crank 19. The horizontal translation of the second carriage 5 is controlled in a similar manner. Figure 2 shows in particular a second trapezoidal thread nut 22 secured to the carriage 5, a second rotary screw 23 mounted in the carriage 3 and secured to a bevel gear 26, to be actuated by means of a second crank 29. The members driving the third carriage 6 in translation along the third axis are not shown. They can also be of the manual type described above, or of another type. Generally, the visible parts of the slides are protected by bellows such as the bellows 30 visible in FIG. 2.

FIG. 3 shows how, in this machining unit, part of the manual drive members illustrated in FIG. 2 have been replaced by other members allowing a numerical control of the translational displacements and of the positioning of the spindle at least along the first two axes of translation. Figure 3 shows more specifically those of these bodies which are provided for the movement and positioning of the first carriage 3 along the vertical axis of the screw 1 3. It is noted first of all that the drive members have been removed manuals 16 to 19 shown in FIG. 2, by putting in place a device with a bi-fold screw 12. 1 3 ai nsi que son pal ier 1 5. La \ ιs 1 3 has been extended by a part 32 which i is coupled, by means of a sleeve 33, to an incremental digital sensor 34 which delivers for example millet the impulses per revolution of the \ ιs 1 3. The sensor 34 is mounted in a housing 35 provided specially for this purpose in the chassis 36 of the first carriage 3. This chassis comprises another housing 37 intended to receive mainly a DC motor 38 actuated by digital control to rotate the screw 1 3 by means of a toothed belt transmission 39. There is also mounted on the building i 36 two detector s limit switch 40, only one of which is visible in the figure. These detectors cooperate with a corresponding element 41 f i xed to the support 1.

In the same way, to control the displacements in horizontal translation of the second carriage 5 by means of the screw 23. the corresponding manual drive members have been removed and members, in the upper part of the first carriage 3, have been installed numerical control similar to those of the screw 1 3. As an indication, there is simply a toothed belt transmission 42 in FIGS. 1 and 3. The numerical control members used in the present invention are generally elements well known and need not be described in detail here. It will simply be mentioned that, for connecting these members to a control post, provision has been made on the pt em icr carriage 3 for a hatch ^ below the assembly area of the manuals 19 and 29. The present invention is not limited to the embodiment described above by way of example, but it extends to any modification or variant obvious to a person skilled in the art. In particular, it is easily understood that the same principles are applicable if the unit has more or less degrees of freedom. Furthermore, it is possible to provide similar members for controlling rotational movements, for example by means of rotary screws on each of which is engaged a corresponding toothed sector.

Furthermore, the construction illustrated by the figures also shows that it makes it possible to completely remove the manual drive members, for example all of the members 11 to 19 for driving in vertical translation of the first carriage 3, to mount at gives them a complete set of numerically controlled drive components. This can be advantageous in particular if it is necessary to have translation screws having a different pitch in each case.

Claims

claims 1. Machining unit convertible from a manual control to a digital control, comprising at least one mobile assembly (3, 5, 6) mounted on a support member (1) so as to be mobile according to at least one degree of freedom, and manual drive means for moving and positioning the entire assembly relative to the support member, characterized in that the manual drive means (1 1, 19, 26, 29) are at less partially removable, and in that the machining unit is provided with reserved housings (35, 37) for receiving at least one digital position sensor (34) and numerically controlled drive means (38 to 42) replacing at least one part of said manual drive means. 2. Machining unit according to claim 1, characterized in that said manual drive means comprise at least one control screw (13, 23) rotatably mounted and engaged in an element mobi the thread (1 2, 22) or toothed, and in that the machining unit comprises, near this screw, at least one housing (35) for a digital rotation sensor (34) coupled to this screw and a housing (37) for a motorized drive member (38, 39) for the screw (13). 3. A machining unit according to claim 2. characterized in that said housing (35) for a digital sensor extends in the extension of one end of the screw (13). 4. Uni tee machining according to claim 3. characterized in that the motorized drive member (38, 39) is coupled to the other end

5. Machining unit according to claim 1. characterized in that the manual drive means (1 1 to 19) are completely removable to be replaced by the digitally controlled drive means. 6. Machining unit according to claim 1, characterized in that the movable assembly comprises a machining head (6) which is movable according to at least three degrees of freedom, and in that the machining unit is arranged to be fitted with numerically controlled drive means according to each degree of freedom. 7. Machining unit according to claims 2 and 6, characterized in that the machining head (6) is movable in translation along three axes, respectively by means of three control screws. 8. Machining unit according to claim 7, characterized in that a respective housing (35) for a digital rotation sensor (34) is reserved near each of the three control screws.