TENSIONING ARRANGEMENT FOR THE ADJUSTMENT OF A WITH AN INTRODUCTION NIPPLE PROVIDED PALLET AT A CLAMPING PLATE

The available invention concerns a tensioning arrangement for the adjustment with an introduction nipple provided of a pallet at a clamping plate, with a housing, which forms a bearing surface for the pallet and exhibits an admission opening to the bearing surface, in which the introduction nipple positionable and by means of a clamping mechanism is fixable, whereby for the turningfirm positioning of the pallet at the housing at the bearing surface at least one groove and/or at least one projection/lead for the interference are intended into a groove trained at the pallet, thereby characterized, daß the projections/leads in the form of pins are trained, which are screwed in into the pallet.

The treatment of metallic workpieces is frequently very complex and can zerspanenden a multiplicity of and cover non-cutting processing steps at different processing machines, in order to make of a blank the finished construction unit. In particular with automated production runs it is substantially, da&szlig thereby; the workpiece with each processing step a defined situation at the respective machine tool takes. For this purpose it is in practice usual to stretch that workpiece which can be worked on first on a pallet and to tighten then the whole unit at the machine table of the respective machine tool. The attachment of the pallets to the Msaschine is made by introduction nipple, those to Rückbzw. Lower surface of the pallets are trained and in high-speed tensioning arrangements to be used and by means of a clamping mechanism be fixed there. In the mass production so the situation of the high-speed tensioning arrangements can be considered as firm machine parameters, so daß it is only necessary to position in each case the workpiece accurately at the pallet. Actual Festund re-clamping the unit made of workpiece and pallet at the machines can take place then very fast and unproblematically, without daß a further positioning is necessary.

With größ eren pallets is usually made if the adjustment at the machine table by several introduction pins, so daß the pallet also against rotating is secured. If at the pallet however only one introduction pin is intended, what in particular with small pallets the case is, additional Ma&szlig must; took to be seized, in order to guarantee, daß the pallet at the tensioning arrangement is positioned in correct position. For this a groove is trained with well-known tensioning arrangements of the frame covers of the tensioning arrangement, on which the pallet is presented, rectangular or squarely trained and in the lower surface of the pallet, in which the cover can intervene. Thereby a certain positioning of the pallet is reached. Unfavorably is however, daß Groove and frame cover over appropriate Paß surfaces to order must, which are expensive in the production, particularly since it is connected with substantial difficulties to hold necessary close tolerance with the additional fit between introduction nipples and nipple drilling. Schließ lich also frequently as unfavorable one regards, daß the frame cover have a rectangular basic form muß. This has among other things as a consequence, daß the pallet only conditionally in the tensioning arrangement into different situations to be re-clamped can. The CH 654,237 reveals a tightener, with which at housings and pallet cooperating plan annular gears are intended, which are bringable for the positioning of the pallet at the housing in interference with one another.

A problem with the well-known tighteners consists however of it, daß the plan annular gears to be very exactly worked must, so that an accurate connection can be guaranteed. This is connected with an appropriate expenditure and costs.

Task of the invention is it to form a tensioning arrangement of the kind initially specified so further daß an positionexact positioning of a pallet is reached in simple way.

This task is erfindungsgemäß thus solved, daß the projections/leads in the form of pins are trained, which are screwed in into the pallet. The pins can be adjusted in axial direction and be positioned by this arrangement thus optimally and if necessary even under pre-loading in the slots. Thus a high positioning accuracy is ereichbar with small manufacturing costs.

In principle it is sufficient, if at the housing only one groove and/or a tap is intended accordingly and at the pallet only one tap and/or a groove. In preferential way however several slots and/or projections/leads are gleichmä&szlig along a pitch circle surrounding the admission in particular at the bearing surface; industrial union distributes arranged, so daß the pallet in different turning situations at the tensioning arrangement is fixable. About it is sufficient to plan several slots to a construction unit and to arrange only one tap at the other construction unit, which intervenes accordingly then depending upon relative turning situation between pallet and tensioning arrangement in one of the slots. Alternatively the number of taps can correspond to the number of slots, so daß at the same time several taps/groove connections exist.

For manufacture-technical reasons it is zweckmäß industrial union to plan the slots in the boundary regions of the housing and/or the frame cover since they can be milled easy from the side there.

Regarding further favourable arrangements of the invention to the Unteransprüche as well as the following explanation of a remark example with reference to the enclosed design one refers. In the design shows

Figure 1

in the profile an execution form of one erfindungsgemäß EN tensioning arrangement with assigned and tightened introduction nipple and

Figure 2

the tensioning arrangement from figure 1 with assigned, but not tightened introduction nipple,

Figure 3

the Spanneinrichung in plan view,

Figure 4

a pallet for adjustment at the tensioning arrangement in the profile and

Figure 5

the pallet from figure 4 in plan view.

In the figures 1 and 2 an execution form of one is erfindungsgemäß EN tensioning arrangement 1 represented. To the tensioning arrangement 1 a cylindrical housing 2 with a above-laterally open lower part 2a, that belongs auß enseitig an extent groove 3 exhibits, in which clamping fixtures can intervene for the adjustment of the tensioning arrangement 1 at a not represented machine table. Into the Zylinderbohrung 4 of the housing 2 a piston 6 is axially movably assigned under education of a pressure chamber 5, whereby the annular gap between Zylinderbohrung 4 and piston 6 by an O-ring 7 is sealed. Into the ground a channel 8 trained in the housing 2 flows to the Zylinderbohrung 4, by which a hydraulic means can be supplied to the pressure chamber 5 as for example oil.

The open top side of the housing lower part 2 is locked by a frame cover 2b, which is screwed onto the housing lower part 2a and forms at its top side a bearing surface 2C for one pallet P which can be fixed. In the bearing surface 2C are äu&szlig in the range; eren edge of cover four slots 9a intended, which are against each other arranged with 90° disalignment in each case, as in particular in figure 3 is well recognizable. The slots 9a, which are conical approaching trained to their ground, serve a pallet P, which exhibits 9b for the positioning, which are bringable with the slots 9a in interference at its lower surface according to four taps. As in figure 4 is shown, the taps 9b are trained in the form of pins, which are screwed in with 90° disalignment into the pallet P in each case, whereby the centers of the taps 9b are arranged on the introduction nipple 12 surrounding pitch circle.

Between the frame cover 2b and the piston 6 a diaphragm spring package 10 is arranged, the piston 6 toward the ground of the Zylinderbohrung 4 subjected.

In the pressure chamber 5 opposite top side of the piston 6 a bag drilling is intended, which forms an admission 11 for an introduction nipple 12, which can be inserted into the admission 11 through-hole 13 intended by one in the frame cover 2b. For the relief of this introduction procedure a capsule-shaped guiing device 14 is intended in the through-hole 13, and to the accurate positioning of the introduction nipple 12 in the tensioning arrangement 1 the upper range of the through-hole 13 in fit dimensioned to a flange 12a of the introduction nipple 12 is.

For the adjustment of the pallet P the introduction nipple 12 into the admission 11 is inserted and the pallet P is positioned in such a way, daß the taps 9b of the pallet P into the slots 9a of the frame cover 2b intervene, so daß the pallet P on the bearing surface 2C for lying comes and rotating the pallet P by the interference of the taps 9b into the slots 9a is prevented. The pallet P can according to the arrangement of slots 9a and tap 9b four around in each case 90° against each other shifted relative turning situations in relation to the tensioning arrangement 1 to take.

The locking of the pallet P takes place then by means of a clamping mechanism. This umfaß t in actually well-known a wise ball cage 15, in which a ball 16 is radially adjustably held, those depending upon piston position into a groove 17 in the wall of the admission after, inserted into the admission 11, 11 auß EN to evade can, so daß an introduction nipple 12 into the ball cage 15 to be inserted or of this taken out can, or by the wall of the admission 11 from such avoiding is prevented and thus in interference with an appropriate Gegenfläche, for example an enular groove, at the introduction nipple 12 held (figure 1).

In the design the figure 1 shows the tensioning arrangement 1 in their clamping position, in which the pressure chamber is pressure-free 5 and which is pressed downward piston 6 by the diaphragm spring package 10, so daß an upper slant 18 of the groove 17 the ball 16 in interference with the introduction nipple 12 holds. If the pressure chamber 5 over the channel 8 with an argument is subjected now, the piston 6 is pressed upward against the resetting force of the diaphragm spring package 10 into the situation represented in figure 2, in that the groove 17 of the ball 16 area läß t, radially after auß to evade EN, so daß the introduction nipple 12 of the tensioning arrangement 1 to be taken out and/or then again into these be inserted can. Like the figure well recognize 2 läß t, is in such a way selected, da&szlig the stroke of the piston 6 thereby; the introduction nipple 12 by the ground of the admission 11 is pressed upward, over daß Remove the introduction nipple 12 to facilitate.

Gemäß the invention exhibits the piston 6 at its pressure chamber-lateral front surface a beginning 19, which is sealed opposite this in one in the ground of the Zylinderbohrung 4 trained recess 20 adjustably led and. The recess 20 forms together with in the beginning 19 a planned, the recess 20 with the ground of the admission 11 for the introduction nipple 12 connecting, for nozzle-like trained channel section 21 and with one of the Gehäuseauß enwandung to the recess 20 extending channel section 22 an air injecting channel 23, which is attached to a not represented source of compressed air. By this air injecting channel 23 when inserting an introduction nipple 12 into the tensioning arrangement 1 or taking of the introduction nipple 12 out compressed air can be injected into the admission 11, around in this way the admission 11 and the introduction nipple 12 by splinters and other impurities in particular in the range of the Paß to clean surfaces and the clamping mechanism. Thereby contamination-caused impairments of the system accuracy can be avoided in reliable way.