FR2789616A1 - Mechanism for translation motion for positioning and indexing components of car body has shaft sliding directly in contact with body without any interposition of intermediate guide bush - Google Patents

Abstract

Mechanism has air cylinder (1) linked to body in light alloy (3) with screws (2). Air jack has rod (4) sliding in centering component (5) and linked to piston. Rod is coupled with steel shaft (6) via axis (7). Axis holds running wheel (8) able to move in groove (9) of body. Shaft slides directly in contact with body without any interposition of intermediate component such as guide bush.

Description

TRANSLATION MOVEMENT DEVICE

  The invention relates to a device for translational movement, in particular for positioning or indexing automobile body parts. Known devices for positioning or indexing automobile body parts generally comprise an actuating means, for example a pneumatic or electric actuator, mounted at the end of a body slidingly receiving a shaft displaceable in translation under the action of said means

actuationally.

  The technique is oriented towards the use of light alloy for the manufacture of the body, which involves the use of a sleeve, a bushing or a smooth guide ring between the light alloy body and the steel shaft movable between a retracted position and an extended position for positioning or positioning

s5 indexing.

  This arrangement is generally satisfactory, but has the disadvantage of an expensive manufacturing due to the number of machining operations to be carried out.

  and the precision of the assembly required to bring the different elements together.

  The object of the invention is to propose a new device for translational movement, in particular for the indexing positioning of automobile body parts, simple and economical to manufacture, easy and precise assembly and

  allowing the use of several different strokes with the same device.

  The subject of the invention is a device for translational movement, in particular for positioning or indexing automobile body parts, of the type comprising a light alloy body slidingly receiving a steel shaft displaceable in translation by means of integral actuation of said body, characterized in that a rare steel slides directly in contact with said body, avoiding any interposition of intermediate element such as a ring

guide or the like.

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  According to other characteristics of the invention: - reaming of the light alloy body receiving the steel shaft is subjected to hard anodization to form a hard surface layer of alumnin with a thickness of between 5 and 50 micrometers, - rare steel receives on its outer surface sliding in the body, a surface hardening treatment, - rare steel carries at least one axis supporting a roller guided in a groove of the body in light alloy, so as to avoid any undesirable rotation of the steel shaft during its translational movement, - each said running roller rolls directly in contact with said groove of the light alloy body, avoiding any interposition of intermediate element of the wear plate or similar type, - each said groove of the light alloy body is subjected on its contact surface with a roller to a hard anodization to form a hard surface layer of al a thickness of between 5 and 50 micrometers, - the device comprises at least one locking pawl in the extended position, preferably elastically prestressed by at least one spring, - the body is suitable for direct mounting of a detection means on the light alloy body, the detection means is arranged to detect the end of a recess formed on the steel shaft, - the steel shaft is machined to present two plates of different lengths and limited by suitable recesses to be detected, so as to allow the

  operation of the device with two different working strokes.

  The invention will be better understood thanks to the description which will follow given to

  by way of nonlimiting example with reference to the accompanying drawings in which: - Figure 1 schematically shows a view along arrow I in Figure 2 im d & sit.if 8.ç. I: 'inv.çnti. n nré.ent.t Lme cure imrnrtan.te. in re-entry nnpition,

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  - Figure 2 shows a sectional view along line II-II of the device of Figure 1, - Figure 3 shows schematically a view along the arrow IM of Figure 4 of a device according to the invention having a hnportante race , in the extended position, - Figure 4 shows schematically a sectional view along line IV-IV of Figure 3 of the device of Figure 3, - Figure 5 shows schematically a view along arrow V of Figure 6 d another device according to the invention, mounted so as to have a short stroke, in the retracted position, - Figure 6 schematically shows a sectional view along line VI-VI of Figure 5 of the device of Figure 5, - the Figure 7 schematically shows a view along arrow VII of Figure 8 of the device of Figures 5 and 6, in the extended position, Figure g schematically shows a sectional view along the line

  VII-VI of Figure 7 of the device of Figures 5 to 7, in the extended position.

  Referring to Figures 1 to 4, a device according to the invention comprises a pneumatic cylinder 1 attached by screws 2 to a body 3 of light alloy. The pneumatic cylinder I comprises a rod 4 slidably mounted in a centering piece 5 and connected to a piston, in a manner known per se. The rod 4 is coupled to a steel shaft 6 by means of an axis 7 with a shouldered head 7a. Axis 7 carries a roller

  8 bearing capable of moving in a groove 9 of the body.

  In FIGS. 1 to 4, the protective cover of the body 3 of light alloy is

  removed, to highlight the interior arrangement of the device according to the invention.

  Preferably, the body 1 also contains a set of locking pawls O10a, 10b applied by springs 11a, 11b against the axis 7 when the device is in its extended position. These locking pawls O10a, 10b as well as

  the springs 1a, 1b are not shown in Figures 2 and 4 for clarity.

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  The protruding end of the steel shaft 6 comprises different machining operations or tapping operations allowing adaptation of position or indexing elements, by screwing

or by pinning.

  According to the invention, the steel shaft 6 slides directly in contact with said body 3 of light alloy. To this end, provision is made, for example, for the bore of the light alloy body 3 receiving the steel shaft 6 to be subjected to hard anodization to form a hard surface layer of alumina with a thickness of between 5 and 50 micrometers. Advantageously, the steel shaft 6 can also receive on its outer surface sliding in the body 3 a surface treatment of carbonitriding or other surface treatment of hardening such as: hard chromium plating, quenching

  superficial, case hardening or nitriding.

  In addition, the roller 8 moves in the groove 9 machined directly in the light alloy body, being directly in contact with this groove, and thus avoiding any interposition of intermediate elements between the roller 8 and the surface of the groove 9 of the body 3 on light alloy. It is also possible to subject the groove 9 of the body 3 of light alloy to hard anodization to form a hard surface layer of alumina with a thickness between 5 and 50 micrometers. These provisions thus enable a simple and economical manufacture of the device according to the invention, and endurance tests have shown that the invention makes it possible to achieve a high number of cycles while keeping good precision.

indexing and positioning.

  Taps 12 and through holes 13 allow the body 3 and the device to be fixed at any desired location. A static seal 14 prevents any penetration of impurities inside the body 3 of the device. The steel shaft 6 is machined to present at least one recess location 15, for example a dish limited by two recesses 15a, 15b. A detection assembly 16 carrying two magnetic detectors 17a, 17b makes it possible to detect the offset 15a, or 15b limiting the edges of the recessed area 15. Thus, in FIG. 2, the offset 15a is detected and indicates the retracted position of the device by transmitting an all or nothing signal via an electrical cable 18 to a programmable controller or

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  a command and control unit not shown; while in Figure 4,

  the setback 1 5b is detected to indicate the extended position of the steel shaft 6.

  In order to separate the steel shaft 6 from the rod 4 of the jack, the pin 7 can be driven out stiffly by a pin passing through a hole 19 made in the body 3 of light alloy and closed during operation by a screw cap 20. This first embodiment of the invention thus makes it possible, owing to the mechanical precision resulting from the elimination of the intermediate clearances during the translation of the steel shaft 6 without any undesirable rotation due to the guidance by the rolling roller 8 cooperating with the groove 9, to obtain excellent positioning or indexing precision of automobile body parts at

  means of simple and economical manufacture.

  With reference to FIGS. 5 to 8, a second embodiment of the invention can make it possible to obtain large strokes of the order of 50 mm as a device shown in FIGS. 1 to 4, and allows in the position shown in the figures 5 to 8 to get lower strokes, just by

modifying the mounting of the device.

  The device comprises an actuating cylinder 21 with a safety system 21a mounted by screws 22 on a body 23 of light alloy. The jack 21 comprises a rod 24 slidably mounted in a centering piece 25. A steel rod 26 is coupled to the rod 24 of the jack via a pin 27 with a shouldered head 27a. The axis 27 advantageously carries a roller 28 for rolling capable of being guided in a groove 29 of the body 23. The guide of the get 28 ds ainur29ducops23. Leguiddugaet28danslarainure 29 prevents any undesirable rotation of the steel shaft 26 during its translational movement resulting from actuation by the jack 21. Pawls 30a, 30b preloaded by springs 31a, 31b can be provided to block the shaft 26 in exit position

Figures 7 and 8.

  Taps 32 and through holes 33 are also provided for mounting the device at any desired location. A seal 44 prevents the

  penetration of impurities inside the body 23 of the device.

  A uaitae on removal 35 lmitt by soft dioroohomonta 35a, 35b is performed on the steel shaft 26, so as to be able to detect the recesses 35a, 35b at

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  using a detection module 36 provided with two sensors 37a, 37b, for example magnetic sensors, and transmit the detection signal via the

  cable 38 to a programmable controller or control means not shown.

  The coupling axis 27 of the rod 24 with the steel shaft 26 can be removed by inserting a pin through a hole 39 after having unscrewed or removed the plug 40. The shaft 26 also carries machining operations suitable for receiving various adaptations for indexing or positioning automotive body parts. In this embodiment, the steel shaft 26 has a through bore 41 substantially parallel to the axis 27, so as to allow re-engagement of a second axis 42 with shouldered head 42a. UL axis 42 carries a roller 43 capable of

  move while being guided in a groove of the light alloy body 23.

  Advantageously, the groove 29 of the light alloy body 23 simultaneously guides the

two rollers 28 and 43.

  Due to the fact that the steel shaft 26 is integral with two rollers 28 and 43, the maximum possible stroke of the shaft 26 is reduced compared to the embodiment of Figures 1 to 4 by a length corresponding to the distance between the geometric axes of the rollers 28 and 43: the embodiment of FIGS. 5 to 8 consequently has a shorter operating stroke than the mode of

realization of Figures 1 to 4.

  However, if one wishes to use the embodiment of FIGS. 1 to 4, it suffices to drive the axes 27 and 42 of the corresponding bores of the shaft 26, to apply to the shaft 26 a rotation of one half -turn around its axis and re-engage

  the only axis 27 provided with its roller 28, without replacing the axis 42 in its bore.

  This arrangement then makes it possible to achieve an operation identical to that of FIGS. 1 to 4, while this time allowing detection of the dropouts 15 a

  and 15b by the detectors 37a, 37b of the detection module 36.

  By carrying out this arrangement in this way, so as to obtain a large operating stroke, the result is a device practically identical to that of FIGS. 1 to 4, if one considers the machining account 41 which must be practiced in the aoier tree

  to be able to engage the second axis 42 with a shouldered head 42a.

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  Advantageously, provision is made in this second embodiment to mount on the head of the shaft 26 a protective cap 44 cooperating with a skirt 45 surrounding the nose of the body 23 of light alloy, so as to prevent any penetration of impurities up to to the seal 34 placed at the end of the nose of the light alloy body 23. This arrangement further improves sealing and reliability

of the device according to the invention.

  The invention described with reference to two particular embodiments is in no way limited thereto, but on the contrary covers any modification of form and any variant of embodiment within the scope and spirit of the invention, essential being that direct contact of the static parts and parts that can be moved in translation provides good accuracy and a long service life for indexing and positioning while

  being simple and economical to manufacture.

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Claims (10)

  1. Device for translational movement, in particular for positioning or indexing automobile body parts, of the type comprising a body (3, 23) of light alloy slidingly receiving a shaft (6, 26) of steel displaceable in translation by means (1, 21) of actuation integral with said body (3, 23), characterized in that the steel shaft (6, 26) slides directly in contact with said body (3, 23), avoiding any interposition of intermediate element   such as a guide ring or the like.   2. Device according to claim 1, characterized in that the bore of the body (3, 23) of light alloy receiving the steel shaft (6, 26) is subjected to a hard anodization to form a hard surface layer of alumina d '' thickness between and 50 micrometers. 3. Device according to claim 1 or claim 2, characterized in cc that the steel shaft (6, 26) receives on its outer surface sliding in the body (3, 23) a surface hardening treatment   4. Device according to any one of the preceding claims,   characterized in that the rare steel (6, 26) carries at least one axis (7, 27, 42) supporting a roller (8, 28, 43) guided in a groove of the light alloy body, so as to avoid any unwanted rotation of the steel shaft (6, 26)   during its translational movement.   5. Device according to claim 4, characterized in that each said rolling roller (8, 28, 43) rolls directly in contact with said groove (9, 29) of the light alloy body (3, 23), avoiding any interposition of intermediate element of like wear plate or the like.   6. Device according to claim 4 or claim 5, characterized in that each said groove (9, 29) of the body (3.23) of light alloy is subjected on its contact surface with a roller to a hard anodization to form a hard surface layer of alumina with a thickness between 5 and 50 micrometers. 9 2789616   7. Device according to any one of the preceding claims,   characterized in that the device comprises at least one locking pawl (10a, b, 30a, 30b) in the extended position, preferably elastically prestressed by at   minus a spring (1 1a, lb, 31a, 31b).   8. Device according to any one of the preceding claims,   characterized in that the body (3, 23) is suitable for direct mounting of a means (16,   26) of detection on the body (3, 23) of light alloy.   9. Device according to claim 8, characterized in that the detection means (16, 36) is arranged to detect the end of a step (15a, 15b, 35a,   35b) made on the steel shaft (6, 26).   10. Device according to any one of the preceding claims,   characterized in that the steel shaft (6, 26) is machined to present two plates (15,) of different lengths and limited by recesses (15a, 15b, 35a, 35b) capable of being detected, so as to allow the operation of the device with   two different work runs.