FR2702979A1 - Automatically-controlled machine tool for the manufacture, by three-axis machining, mechanical components from a bar having several faces - Google Patents

Abstract

a) Automatically-controlled machine tool. b) Machine tool characterised by: - a reference plane (27) defined by the bar feed loader (magazine) (30), on which plane the bar (20) bears while it is being machined and rotated on itself; - a mechanism (40) for driving the bar; - a fixed reference plane (67); - an indexing chuck (51) through which the bar (20) to be machined passes; - a rotation means (54) for driving the rotation of the indexing chuck (51); - a means (53) for driving the indexing chuck (51) vertically in order to raise and lower the chuck (51) while it is rotating with the bar (20), leaving the bar (20) to bear, during this rotation, on the reference plane (27) of the bar feed loader (30) and on the reference plane (67).

Description

"Automatic control machine tool for
manufacturing by machining along three axes of parts
mechanical, from a multi-sided bar "
The present invention relates to a machine tool machining with automatic control for the manufacture by machining along three axes of mechanical parts, from a bar with several faces, comprising in order and along the axis of advancement of the bar during machining - a bar feeder magazine for bar feeding
to be machined, - a bar rotation mechanism to turn the
bar on itself and allow machining of dif
different sides of the room still attached to the
bar as well as its sectioning, - a machining table formed by a machining vice in
which is clamped the bar during machining, - a machining head located above the table
machining, - a cutting means to separate the workpiece from the bar.

 Such a type of machine is used in particular by metalworkers, that is to say manufacturers of metal fittings or frames and more generally of mechanical parts, which frequently use mechanical parts machined from bars, machining. being of the milling, folding, etc. type

 Traditional machining machines have a machining table that moves along at least two axes, which makes it very difficult, if not impossible, to mass produce multiple mechanical parts in the bar. The term bar is used here in a very general sense since it can cover metal profiles, in particular hollow or even open profiles such as those used in metalwork.

In the case of tubular profiles the axis of the bar is that passing through the center of the closed polygon of the section of the bar and in the case of an open profile whose simplest form is an angle, the axis taken in the sense of the present invention is that passing through the closed polygon (in general a rectangle or a square) of the "section of the profile
Thus in a known machine of the type defined above, the bar to be machined is carried in a series of spectacles and an indexing mandrel (fixed mandrel) the spectacles comprise intermediate parts (shaped furs) adapted to each profile which are therefore different. They must be changed each time the bar shape changes.

 This not only requires multiple sets of shaped furs, adapted to each profile to be machined, but entails significant transformation and adjustment work with each profile change (depending on manufacturing needs).

 However, this constitutes an extremely annoying obstacle to the complete automation of a production for large series of parts machined in different profiles.

 The means used in this known machine for moving the bar are very important since the bar is carried by the glasses while being clamped in the machining scope. The bar rotates around its axis in the glasses, with the shaped furs; it advances along its axis to position itself under the machining and cutting tool.

 In addition to the above drawbacks, large masses must be moved (a bar weighs up to 100-150 kg), the positioning accuracy of the bar is a delicate problem.

 Due to the necessary rotation of the bar to successively present its different faces for machining, the bar is clamped only between the jaws of a machining vice, opening to allow rotations. There is therefore no reference to the position of the bar apart from its clamping in the vice.

 The present invention aims to remedy these drawbacks and proposes to develop a machine tool for machining allowing precise machining of any profile according to the parts to be produced, without requiring any transformation of the equipment. of the machine, and making it possible to automatically switch from one profile to another without stopping manufacturing, according to a program.

To this end the invention relates to a machine of the type defined above characterized by - a reference plane defined by the on-board store
reur, plane on which the bar rests during
the machining and its rotation on itself for the chan
front facing, - a bar drive mechanism for driving
the bar along its axis by pushing or ti
rant for its installation, its machining and / or the
transition from one room to the next, - a fixed reference plane defined by the table
identical to the reference plane is defined
by the support of the embarrassing and constituent store
the support surface for the part during its rotation
and its machining,
this machining table comprising a machining vice with
symmetrical opening / closing with respect to a plane
of vertical symmetry, - the bar rotation mechanism comprising
an indexing mandrel traversed by the tool bar
ner and provided with an inner jaw to hold
bar,
. a rotation means for controlling the rotation of the
indexing mandrel on demand, according to the face to
present for machining by rotating the
mandrel around its axis,
. a means for vertically driving the in mandrel
dexing to raise and lower so
controlled by a servo means, the man
drin during its rotation with the bar leaving
the bar will be supported during this rotation on the
reference map of the bar feeder store and on the
reference plane of the machining table.

 Thus, according to the invention, the machine is versatile, without requiring any transformation to move from one profile to another and this while providing excellent positioning accuracy of the bar therefore machining.

 During machining the bar rests on the support plane of the bar loader magazine, being taken in the indexing mandrel and in the machining vice, the latter also ensuring the positioning of the bar by its reference plane.

 During the rotation of the bar around its axis, this bar is held in the indexing mandrel.

 The whole machine is considerably simpler than known machines and its automation can be very advanced, particularly in the case of a numerically controlled machine since it can work fully automatically according to a predefined work program and using the if necessary a succession of bars of different sections.

 According to the invention, the machining vice of the machining table is a vice with symmetrical opening / closing with respect to a vertical plane of symmetry, so that a bar during machining always has its axis of longitudinal symmetry maintained in the same vertical plane of symmetry. Thus, with the architecture specific to the present invention, the bar to be machined, which always remains in abutment on the fixed reference plane, is only manipulated in two ways on the one hand in rotation on itself to present its different faces to the machining head, on the other hand longitudinally to move from one part to the next.

 According to a preferred embodiment, the means for controlling the vertical movement of the mandrel comprises a level detection means which is a feeler in the form of a roller with a horizontal axis disposed transversely in abutment below the bar. This embodiment is obviously not the only one, but it has the advantage of simplicity.

 During the passage from one part to the next, the finished part is separated by means of a cutting to be carried out with an adjustable cutting head. This cutting head is adjustable because the cutting is not necessarily carried out in a transverse direction. perpendicular to the axis of the bar; in the case in particular of metalwork, cutting-off must often be carried out at various angles; according to the present invention, the angular movement of the cutting head is only 45 "; in fact this limited angular movement is sufficient to carry out all the possible cutting operations since it suffices to rotate the bar on itself by 1800 so that the cutting angle is always reduced to a value less than or equal to 45 ".

 Of course, to obtain the most complete automation possible, the machine tool according to the invention will preferably be controlled by a numerical control, and, for the same reason, the machining head will be equipped with a magazine, example, ten tools, a tool measurer and a POP (Point of Origin Piece) rod.

The present invention will be clearly understood in the light of the description of a nonlimiting example of an embodiment illustrated by the appended drawings among which - FIGS. 1A and 1B show two types of bar and
of part machined in these bars with a machine
according to the invention, - Figure 2 shows in perspective the architecture
of a machine according to the invention, - Figure 3 shows in side view a mechanism
of rotation according to the invention, - Figures 3A, 3B and 3C illustrate, seen at the end, a
bar rotation movement obtained with the mechanic
rotation nism according to the invention.

 To better explain the purpose and operation of the machine according to the invention, two examples of machining on bars will be described below.

 Figures 1A and 1B show, without limitation, two types of bar that can be machined with the machine tool according to the invention to obtain mechanical parts by machining of the milling type. The parts shown by way of example are relatively simple, but it is clear that more complex parts can also be envisaged with the L-shaped bar 10 in FIG. 1A, parts 11, 12, 13 can be produced each comprising only one bore and a slightly bevelled side which results in the material falling 01, 02, 03 in this extremely simple example, the manufacture of a part requires only three operations: a bore and two cut-offs, the one square and one slightly beveled; however with an automatic machine tool it will be necessary to provide bar handling mechanisms for drilling and the two cut-offs; in FIG. 1B, the bar 20 is a hollow parallelepiped profile in which the parts 21, 22, 23 are machined, each one comprising a bore on one face, a grooving on another face, and two sections, one at right angles and the other bevel so that to avoid loss of material, the parts 21, 22, 23 are nested two by two; the machining cycle is therefore more complex here despite the relative simplicity of the part; in this example the odd pieces 21, 23 etc are identical to the even pieces 22 etc, it is clear that this is not an obligation. These two relatively simple examples, FIG. 1A and FIG. 1B, illustrate the complexity of a machine tool for machining allowing their automatic manufacture from a bar of 100 kg and being able to measure up to six meters in length.

 In FIG. 2 the general architecture of a machine tool 1 for machining according to the invention is shown; generally the various manipulation mechanisms of the machine tool 1 are arranged symmetrically around the vertical plane of symmetry 29 so that a bar 20, here similar to that shown in FIG. 1B, always has machining, its axis 28 of longitudinal symmetry maintained in this vertical plane of symmetry 29. The machine tool 1 comprises the following elements - a bar loader magazine, - a bar drive mechanism 40, - a bar rotation mechanism 50, - a machining table 60, - a machining head 70, and - a cutting head 80.

 It can immediately be noted that the bearing surface 67 of the machining table 60 is fixed, which defines a fixed reference plane 67 which is the same as the support plane 27 for the bar loader magazine 30.

 The bar feeder magazine 30 is here succinctly shown with three horizontal rollers located at the same level to support one face of the bar 20; the bar 20 has been shown in a simplified manner, it is clear that in normal operation the end of the most distant bar 20 would have already been machined and sectioned; with the bar feeder magazine 30, an automatic feed device for the bars to be machined, not shown, can be provided, such as a strap device. The bar feeder magazine 30 is, during machining, constantly used as a support for the part of the bar not yet machined.

 The drive mechanism 40 is a mechanism which is only used for advancing the bar during the manufacture of each new part; this drive mechanism 40 essentially comprises a jaw 41, the re / closure opening of which is symmetrical relative to the vertical plane of symmetry 29, and a bar advancement mechanism 42; the bar advance mechanism 42 can also move the bar back when it has been deliberately too advanced, for example to allow cutting off outside the bearing surface of the machining table.

The rotation mechanism 50, which is also illustrated in FIGS. 3, 3A, 3B and 3C with the same references, essentially comprises a rotary indexing mandrel 51 provided with an internal jaw 52 for holding the bar 20, a means of rotation 54 for, on request, rotating the indexing mandrel about its axis, and a vertical drive means 53 for the indexing mandrel 51; this means 53 is controlled by a servo device 58 which reacts to the indications 56, 57 supplied by a feeler roller 55 with a horizontal axis disposed transversely in support below the bar 20; the vertical drive means 53 may for example be a hydraulic cylinder; according to the invention, as illustrated in FIGS. 3A, 3B and 3C, the distance between the axis 28 of the bar (whose section is not circular) and the fixed reference plane 27, 67 on which the bar is always in support, is variable as the bar rotates (distances D1, D2,
D3).

 The machining table 60 is fixed and its machining support plane constitutes the fixed reference plane 67; the machining table 60 is provided with a vice 61 with symmetrical opening / closing with respect to the vertical plane of symmetry 29.

The machining head 70 is located above the machining table 60; in addition to the rotational movement of the machining tool, it can move in the three directions X, Y and Z for the needs of machining; it is clear from this figure that the movement in the X axis of the machining head 70 is completely independent of the movement 42 of the drive mechanism 40 of the bar; thus each of these two movements can be obtained with specific means depending on the effort and precision required; the machining head 70 can be associated with a tool magazine, for example ten in number, a tool measurer and a POP (Point of Origin) rod
Room).

 The machine tool of machining according to the invention comprises a cutting head 80 with a rotary cutting disc 81 which can descend 82 onto the bar 20 to cut it either orthogonally, as shown, or non-orthogonally after a angular displacement 83; the angular movement 83 of the cutting head 80 can be limited to 45 "since it then suffices to rotate the bar 20 by 180- on itself by means of the rotation device 50 to obtain all the cutting angles between 0 and 90.

 The operation of the machine 1 will now be described on the understanding that it is provided with known devices, and therefore neither shown nor described, such as digital control, position detector, control device and the like. A bar 20 being present on the rollers of the bar feeder magazine 30, this is advanced to the machining table 60 by means of the drive mechanism 40; during this advance, the machining vice 61 and the inner jaw 52 of the indexing mandrel 51 are in the open position; then, the vice 61 is clamped on the bar 20 and the machining of the face of the bar 20 which is located under the machining head 70 can be carried out; at the end of the machining of this face, the vice 61 is loosened and the inner jaw 52 of the rotation mechanism 50 comes to tighten the bar 20 and a rotation, for example that shown in FIGS. 3A, 3B, 3C, is performed during which the axis 28 of the bar 20 is still maintained in the vertical plane of symmetry 29, this maneuver being carried out without excessive force on the indexing mandrel 51 since, due to the controlled vertical drive means 53, the weight of the bar 20 is always, at least partially, carried by the bar loader magazine and the machining table 67; after rotation, the inner jaw 52 is loosened, the machining vice 61 is tightened, and the machining of another face of the bar 20 with the machining head 70 can be carried out; it is thus possible to machine all the faces of the bar 20, and it is even possible, if necessary, to envisage machining the same face in several stages; at the end of the machining, the vice 61 is loosened, and the drive mechanism 40 again advances the bar to arrange it adequately for cutting by the cutting head 80 as a variant, due to complete independence of the movements of the various mechanisms, two parts can be machined before cutting, this may be the case for parts 21 and 22 in FIG. 1B which can be advantageous to machine two by two before double cut to separate them; thus with a numerically controlled machining machine tool whose architecture conforms to the present invention, the automatic manufacture of mechanical parts by machining along three axes is possible according to many variants by means of the implementation of the mechanisms described. which are particularly simple and economical in comparison with those of the prior art.

Claims (4)

 1) Machine tool with automatic control for the manufacture of parts (11, 12, 13, 21, 22, 23) by machining along three axes (X, Y, Z) of a bar (10, 20) with several faces, comprising in order and along the axis of advance (28, X) of the bar during machining - a bar feeder for feeding the bars  to be machined, - a bar rotation mechanism to turn the  bar on itself and allow machining of dif  different sides of the room still attached to the  bar as well as its sectioning, - a machining table formed by a machining vice in  which is clamped the bar during machining, - a machining head located above the table  machining, - a cutting means to separate the workpiece from the bar, machine tool characterized by - a reference plane (27) defined by the magazine em  coxswain (30), plane on which the bar (20) rests  during machining and its rotation on itself for  changing the face, - a bar driving mechanism (40) for  drag the bar along its axis (28, X) in the push  health or by pulling it for its installation, its usi  swim and / or move from one room to the next, - a fixed reference plane (67) defined by the table  machining (60) identical to the reference plane (27)  defined by the support of the bar feeder magazine (30) and  constituting the support surface for the part during  its rotation and its machining,  this machining table (60) comprising a machining vice  swim (61) with symmetrical opening / closing by rap  port to a vertical plane of symmetry (29), - the bar rotation mechanism (50) comprising  an indexing mandrel (51) traversed by the bar  machine (20) and provided with an inner jaw  (52) to hold the bar,  rotation means (54) for controlling the rota  tion of the indexing mandrel (51) on request, following  the face to be presented for machining by making  turn the mandrel (51) around its axis,  a vertical drive means (53) of the mandrel  indexing (51) for raising and lowering  way controlled by a servo means  (58), the mandrel (51) during its rotation with the  bar (20) leaving the bar (20) to rest  during this rotation on the reference plane  (27) of the bar loader store (30) and on the plan of  reference (67) of the machining table (60).  2) Machine tool according to claim 1, characterized in that the means for controlling the vertical movement (53) of the telescope (51) comprises a level detection means which is a shaped probe (55) horizontal axis roller arranged transversely in support below the bar.  3) Machine tool machine according to any one of the preceding claims, characterized in that it further comprises a head (80) of adjustable cutting, whose angular movement is 45 ".  4) Machining machine tool according to any one of the preceding claims, characterized in that it is a numerically controlled machine tool.