Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23G—THREAD CUTTING; WORKING OF SCREWS, BOLT HEADS, OR NUTS, IN CONJUNCTION THEREWITH
  • B23G11/00—Feeding or discharging mechanisms combined with, or arranged in, or specially adapted for use in connection with, thread-cutting machines

Definitions

• the present invention relates to an automatic processing machine for mechanical parts and in particular for machining and / or tapping nuts, comprising a supply device designed to bring said parts to at least one processing unit.
• the current machines which provide the tapping of the nuts do not include any device for very precisely positioning the nuts so that the axis of the tap is completely perpenicular to the upper and lower generally hexagonal faces of said nuts.
• automated assembly carried out by assembly robots which is increasingly common, especially in the automotive industry, requires very high precision in the manufacture of nuts.
• the axis of the thread must be perpendicular to the plane of the main faces with minimal tolerance, so that the nut can be correctly engaged and screwed onto the corresponding bolt.
• the present invention proposes to overcome this drawback by providing a machine which makes it possible to carry out the machining and / or tapping of the nuts with sufficient precision to allow the mounting of these nuts by assembly robots.
• the processing machine is characterized in that the feeding device comprises means for bringing one piece after another into a central machining unit, in that this central machining unit comprises positioning members for holding these parts during their machining and machining members for carrying out said machining, and in that the machine also comprises two lateral processing units arranged on either side of the central processing unit machining, distributing means for successively distributing to each of these lateral processing units a part previously machined by the central machining unit, as well as drive and control means for generating the movements of the moving parts.
• the feed device comprises a manipulator arm arranged to pick up a part at a given supply point and to bring it towards the positioning members.
• the positioning members advantageously comprise a mandrel with two jaws with concentric clamping.
• the central machining unit preferably comprises an upper spindle and a lower spindle, respectively mounted on two slides arranged to ensure the upward and downward movements of these spindles.
• the distributing means preferably comprise a slide with transverse displacement arranged to push a previously machined part from the machining zone towards the tapping zone.
• the manipulator arm is advantageously arranged to bring a part to be treated below a previously brought part which has undergone said machining, and to lift said machined part.
• the slide with transverse displacement is mounted above the clamping mandrel and its trajectory passes through the position occupied by said machined part raised by the next part brought by the manipulator arm.
• This slider preferably comprises a pusher arranged to push said part during its transverse displacement, a retaining tab arranged to limit the displacement in height of this part during its transverse displacement and a plane lower face of height reference for the next part.
• the slide is arranged to effect a transverse movement right-left or vice versa and vice versa to bring a first part to a first lateral processing unit, and to effect a transverse movement left-right or vice versa. vice versa, to bring a second part to the second lateral treatment unit.
• the slide with transverse movement is controlled by a mechanism comprising two cams and two master cylinders controlled by these cams.
• the manipulator arm is hydraulically controlled respectively by two cams associated respectively with two master cylinders.
• the frame advantageously includes a lubricant recycling tank containing a recycling pump.
• fig. 1 represents a side view in elevation of the machine according to the invention
• fig. 2 shows a front view of the machine according to FIG. 1,
• fig. 3 represents a front view of the two-jaw clamping mandrel and of the parts distributor slide
• fig. shows a side view of the clamping mandrel and the distributor slide
• fig. 5 shows a ' bottom view illustrating the mandrel and the slide as well as the drive mechanism of this slide.
• the machine 10 shown has a frame 1 1 on which are mounted a supply device 12 designed to bring the nuts to be machined and tapped to a central machining unit 13 and two lateral tapping units 1 and 15 arranged on either side of the central machining unit 13, and various control and drive means which will be described in more detail below.
• the nuts are brought by a slide 16 in the shape of an arc of a circle and taken one by one by a clamping arm 17 which brings them into position in the central machining unit 13.
• a clamping mandrel keeps them during the entire machining period which can consist of a single or double-sided surfacing or any other machining operation such as chamfering etc.
• the nuts are distributed alternately to the right and to the left towards the two lateral tapping units.
• the double tapping unit saves considerable time. Indeed, it is estimated that the duration of the machining performed by the central machining unit 13 is substantially equal to half the time required for tapping performed by the lateral tapping units.
• the existence of two tapping units makes it possible to carry out a complete machining while the two tapping units each carry out a half tapping operation, that is to say globally a complete tapping.
• the nuts are removed on a ramp (not shown) from where they can be taken up, for example, by a belt conveyor, a bucket chain or any other suitable device.
• the shavings and the lubricant are recovered by tanks 18 and 19.
• the nuts are brought one by one, by a distributor of the vibrator type or the like, to the upper entry of the slide 16 from where they slide one behind the other to the lower point d 'where they are supported by the manipulator arm 17 according to a movement which will be described later.
• the central machining unit 13 of a known type consists, in this case, of a lower spindle 20 driven by a drive motor 21 coupled to the spindle axis by a masked belt 22 by a protective cover 23, as well as an upper spindle 24 driven by a drive motor 25 coupled to the spindle axis by a belt 26 masked by a protective cover 27.
• the lower spindle 20 is mounted on a slide 28 arranged to allow said pin to be moved in a vertical direction. This up-down movement is controlled by an appropriate electronic circuit, housed in a housing 29.
• a mechanical end-of-travel stop 30, adjustable in position is mounted on a fixed support 31 secured to one of the elements of the slide 28 , and limits the stroke of the upward movement of the lower spindle.
• the upper pin 24 is mounted on a slide 32 arranged to allow the said pin to be moved in a vertical direction. This up-down movement is controlled by appropriate electrical switches housed in a housing 33.
• a mechanical limit stop 34, adjustable in position, is mounted on a fixed support 35 secured to one of the elements of the slide 32 and limits the travel of the downward movement of the upper spindle.
• the lower and upper pins are designed to provide machining, respectively on the lower face and the upper face of a nut and / or in the bore of the nut, these operations can be carried out individually or jointly.
• Each of the two lateral tapping units 14 and 15 of known type, as shown in FIG. 2, comprises a spindle 40 fitted with a tool holder 41 and driven by a drive motor 42.
• the assembly is mounted on a slide 43 which provides the height adjustment in a vertical direction of the tapping units.
• the slides 43 are mechanically actuated.
• the lower part of the frame contains a lubricant tank 52 in which a recycling pump 53 plunges, the role of which is to circulate the lubricant which sprinkles the machining and tapping tools during their work.
• a perforated sheet 54 retains the chips which fall into the tanks 18 and 19 which can also receive the machined and threaded nuts, unless the latter are directly removed by a conveyor belt or the like (not shown).
• a deflector 55 is mounted on the central machining unit.
• the corresponding mechanism comprises four master cylinders 44 (44 'hidden in fig. 1) and 45 (45' also hidden in fig. 1) whose phases are controlled by four cams 46, 47 and 46 ', 47', these the latter being hidden in fig. 1.
• the cams 46 and 47 are mounted on a rotary shaft 48 driven by a reduction pulley 49 which controls the movements of the manipulator arm 17, and the cams 46 'and 47' are mounted on a shaft 48 'driven in a ratio of 1 / 2 by the pinions 50 (the latter also being masked in FIG. 1), which control the movements of the slide 57.
• This mechanical assembly is mounted in a housing of the frame 1 1, the base of which is constituted by an oil tank 51 in which the cams 46, 47, 46 'and 47' are immersed. The mechanism described above ensures synchronization of the movements of the manipulator arm 17 and of the transverse transverse slide 57.
• the clamping mandrel 56 of known type essentially consists of a body 60 and two jaws 61 sliding inside this body. As mentioned above, these jaws are concentrically clamped and are actuated symmetrically by a hydraulic cylinder (not shown) incorporated in the body 60.
• the jaws 61 are interchangeable and can be replaced according to the dimensions of the parts to be machined and tapped.
• the distribution slide 57 essentially consists of a body 70 mounted on the cylinder of a hydraulic cylinder 71 between two compression springs 72 and 73 whose role is to absorb excessive stresses due, if necessary, to a blockage of the slide if a part gets stuck during its lateral movement which must bring it from the central machining unit towards one of the lateral tapping units and compensate for the variations of the strokes due to the different dimensions of the parts.
• the hydraulic control liquid is injected through the opening 74 into the central duct 75 of the piston rod 76, which has the effect of displacing the cylinder of the jack 71 to which the body 70 of the distributor slide 57.
• this body carries a support 77 to which is fixed, for example by means of screws 78, the distributor plate 79 of the slide 57.
• This plate comprises at each of its ends, on the one hand a pusher 80 having for example an angular cutout which adapts to the profile of the nuts to be tapped, and on the other hand a retaining tab 81 which extends beyond the pusher to retain the parts to be treated and prevent them from being lifted during their transfer from the central machining unit to one either side of the tapping units.
• a support 82 is mounted which receives two guides 83.
• the parts pushed by the distributor slide are guided by the guide 83 and braked by a spring 84.
• the stroke of the slide is determined in such a way that the nuts thus braked are brought into the exact position in which they will be treated. After removing the tap, the nut remains in place and will be pushed back by the next nut brought into the working position by the slide.
• the manipulator arm When the parts to be treated are nuts, the manipulator arm is positioned under the feed ramp, takes the nut directly placed above its end, and moves it on a trajectory which is a combination of a rotational movement around a vertical axis and a translational movement along a vertical axis, to bring it below the central machining unit.
• the nut carried by the manipulator arm is brought directly below the nut previously brought in and momentarily retained by the jaws of the clamping mandrel.
• the manipulator arm moves from bottom to top and lifts the previous nut, the clamping jaws being loosened beforehand to release the nut whose machining is finished.
• the lower nut is then supported by the jaws of the clamping mandrel and the upper nut is carried freely by the lower nut.
• the distributor slide or more precisely the retaining lug 81 of this slide is brought previously into position above the upper nut and prevents its overturning.
• the lower surface of the pusher 80 constitutes a height reference which ensures the precise positioning of the lower nut during the mid-stroke tightening of the pusher 80.
• the distributor slide moves, for example, from left to right to bring the upper nut into position under the right side tapping unit.
• the thread nut pushes the nut previously tapped which falls into the receiving tank or which is discharged by an appropriate device.
• the slider then remains on the right side of the central machining unit until a new nut is brought in by the manipulator arm and the previously machined nut is lifted by the next nut.
• the distributor slide then moves from right to left to bring the upper nut into position under the left side tapping unit.
• the machining is carried out twice as fast as the tapping and this is the reason why two tapping units have been provided for a central machining unit.
• the transverse displacement slide 57 can be associated with chucks of known type, with concentric tightening, controlled hydraulically or pneumatically.
• the mandrels would appear directly under the central machining unit 13 and the lateral tapping units 14, 15, which would make it possible to keep the part maintained during all movements.
• the machine according to the invention comprises a central machining unit which is for example a surfacing or chamfering unit, etc., and two lateral processing units which are arranged to perform the tapping of the nuts brought by the manipulator arm, other operations could be carried out on this machine depending on the parts which one plans to treat and the results which one wishes to obtain.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Feeding Of Workpieces (AREA)
• Processing Of Meat And Fish (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=9354726

Family Applications (1)

Country Status (4)

Cited By (1)

Families Citing this family (6)

Family Cites Families (3)

• 1987
  • 1987-09-07 FR FR8712472A patent/FR2620065B1/fr not_active Expired
• 1988
  • 1988-08-03 EP EP19880907329 patent/EP0343195A1/de not_active Withdrawn
  • 1988-08-03 WO PCT/FR1988/000402 patent/WO1989002331A1/fr not_active Application Discontinuation
  • 1988-09-06 ES ES8802670U patent/ES1007366Y/es not_active Expired

Non-Patent Citations (1)

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