DD264873B1 - AUTOMATIC CLAMPING SYSTEM - Google Patents

Description

For this 1 page drawing

Field of application of the invention

The automatic clamping system is provided for the central recording and axial clamping of bush-shaped parts, in particular of such sockets deron inner shape for centering and recording during the operation external cylindrical grinding Schrägeinstechverfahren can not find use, but still the demand for a high geometric accuracy of the outside diameter to plan page of the workpiece or the pitch circle of, for example, bevel gear bushings to meet.

Characteristic of the known technical solutions

For the recording, centering and driving of bush-shaped workpieces, a variety of grips that work on a variety of principles have become known. The recording was previously only on mostly workpiece-bound, expandable Spitzer thorns. When used, an internal bore that is precision machined to a certain degree is indispensable. The entrainment of the workpiece, which has been pushed manually onto the mandrel is achieved by spreading the existing of several segments spreadable mandrel, which at the same time takes place a centering of the workpiece after the machined inner bore. The mandrel is recorded in the usual way between the two grains. For short workpieces of the type mentioned also a flying arranged expanding mandrel can be used in conjunction with a self-pressing counter-holder, as has become known from the DO-PS 213 382, use. In this case, a finished inner bore is also required.

For a central fixation and axial clamping of workpieces of the type mentioned, DD-WP 232001 has disclosed a "mandrel" intended for turning operations in which the workpiece to be machined must be centered in the finished bore for accuracy. For this purpose, it is provided that centering jaws are in operative connection with a compression spring and that jaws each form a key piece, a lag screw and a tie rod with a clamping drive in operative connection and that between a pull rod and a lid, a gap is present.

The disadvantage of this mandrel that this is only suitable for relatively short workpieces, the bore must be finished.

The provided for the automatic centering and axial clamping moving parts are complicated and expensive to manufacture, exposed and thus exposed to contamination by the fineness of the chips and the abrasive abrasion, which can lead to disturbances and therefore for automatic operation in external cylindrical grinding in any way suitable is.

Furthermore, DE-AS 2346252 entitled "Tool holding device for an internal cylindrical grinding machine" was known, which also deals with the centering and axial clamping of bush-shaped workpieces.

For aligning the workpiece axis on the axis of the work spindle (workpiece spindle) is provided in this case that a conical portion of an actuating device in combination with a gauge axially into the workpiece bore can be inserted. The tension of the workpiece is carried out after centering by mechanically swiveling claws, which engage in recesses or duich breaks on the workpiece and press the workpiece axially against a clamping plate connected to the workpiece spindle.

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This workpiece holding device has been developed especially for internal cylindrical grinding and also requires a

pre-machined bore for centering as well as engagement or engagement possibilities for the arranged around the outer diameter, radially and axially acting clamping jaws.

A use of this system for centering and clamping workpieces of the type mentioned is out

not possible for several reasons. So axial clamping by means of claws can not be done because it is the space in the

Do not allow external cylindrical grinding. There is also, as with the DO-WP 232001 the risk of contamination and the

associated disadvantages for performing an automatic operation.

From this state of the art is deducible that so far for the automatic centering and axial clamping of workpieces de

cited type for the implementation of the operation external cylindrical grinding in Schräginstechverfahren yet no corresponding automatic or automatable clamping system is known, which meets the demand for the highest precision and availability.

Due to this situation, it has been necessary to make the alignment and clamping manually, which in addition

Labor productivity and the quality was negatively influenced.

Object of the invention

It should be eliminated the mentioned disadvantages. The creation of an automatic clamping system ensures an increase in labor productivity with constant adherence to high quality parameters. In addition, a high availability and ease of conversion to another workpiece is to ensure.

Explanation of the essence of the invention

The object of the invention is to provide an automatic clamping system for such bush-shaped parts, in particular bevel gear bushings, in which the inner shape is not available due to the design for a central receptacle for the operation external cylindrical grinding. Despite this fact, a high geometric accuracy with safety in automatic operation can be achieved in the workpieces.

It is the angularity of the outer diameter to the plan side or to the pitch circle of the teeth with a good cylindricity of the outer diameter.

The new automatic clamping system is designed so that the required clamping forces do not jeopardize the long-term accuracy of the workpiece spindle bearing. It should be used for relatively small workpieces in the clamping system for diameter, the conversion to a different workpiece size without great expense should be possible. According to the invention, the object is achieved in that a piston rod has a threaded bore into which a collet-like connector in the axial direction, co-equal to the workpiece spindle is provided several times with slots and approximately in the middle of the connector with an outer cone and at its front end with a collar , and so is associated with tensioning and relaxing the tensioning system. In this case, the outer cone of the collet-like connecting piece with an inner cone, which is located in the longitudinal bore of an auxiliary mandrel of a threaded bush, operatively connected.

embodiment

The invention will be explained below using an exemplary embodiment

 In the accompanying drawing shows:

Fig. 1: an inventive Spennsystem in working position, in section. A piston rod 1 is arranged coaxially in the workpiece spindle 2 of an external cylindrical grinding machine. The piston rod 1

is provided with a head 3 which is located in the front part of the workpiece spindle 2 and is oil-tight and torsion-free. The piston rod 1 is in a known manner with an axially acting hydraulic drive in connection. In that

Head 3 of the piston rod 1 is an axially extending threaded bore 5, in which a collet-like trained Connector 4 is screwed in the front side. The connector 4 is provided with a plurality of axially extending slots 4.1, and approximately in the middle of his Longitudinal extent is an outer cone 4.2. The front part of the workpiece spindle 2 is equipped with an exchangeable intermediate ring 2.1, which is for receiving

various, workpiece-specific face plates used. In our example it is a face plate 2.2 connected with a

Ball ring 2.3, in which the number of balls with the number of teeth of the bevel gear teeth 8.1 of the workpiece 8 matches. At the intermediate ring 2.1, an auxiliary mandrel 6 is also interchangeable attached. The auxiliary mandrel β has the shape of a collar bushing, in

which is screwed in the longitudinal direction of a threaded bushing 6.2. The threaded bush 6.2 is at the rear end, which on the

Intermediate ring is directed 2.1, provided with an inner cone 6.1, which cooperates with the outer cone 4.2. In Axial direction is a pivotable in the working plane Andrückeinheit 7 with a pressure plate 7.1 and

an inner collar bushing 7.2.

The bore in the collar is held in diameter so that the front collar 4.3 dos connector 4 in

compressed state can be passed.

At rest, without inserted workpiece 8, the piston rod 1 is in its front end position, causing the Connecting piece 4, caused by the displaced against the inner cone 6.1 outer cone 4.2, in compressed State is. In this state, it is possible to extend the pressing unit 7 from the clamping plane and radially

swerve. After depositing einos workpiece 8 on the auxiliary mandrel β and after completion of the centering is

the pressure unit 7 is pivoted radially into the clamping plane and moved axially against the rear plane surface of the workpiece 8, wherein the compressed connector 4 is inserted into the interior of the inner liner 7.2. Due to the subsequent return movement of the piston rod 1 together with the connecting piece 4, the outerconcept 4.2 is separated from the inner cone 6.1 and thus the connecting piece 4 is spread apart, so that the collar 4. 3 comes to rest behind the collar of the inner collar bushing 7.2.

The further movement of the piston rod 1 causes the pressure plate 7.1 is pulled against the workpiece 8 and thus such a frictional connection takes place, which has no additional burden on the storage of the workpiece spindle 2 result. The accuracy of storage is maintained over a long period of time.

Claims (2)

1. Automatic clamping system for a central recording and axial clamping by hydraulic drive of such buchs6nförmigen parts, in particular bevel gear bushings whose internal shape is not suitable for the centric recording on a mandrel due to their design, using a connected to a rotating workpiece spindle face plate with workpiece-specific plan system or Fixation of the pitch circle of the bevel gear teeth on a ball ring and use of an auxiliary mandrel and a radially on the axis of the workpiece spindle and Hilfsdcrnes einschwenkbaren and provided with a drive Andrückeinheit their Anlagering via an upstream spherical cap to compensate for existing on the workpiece Planparallelitätsfehlern and the hydraulic drive with a piston rod is connected, characterized in that the piston rod (1) has a threaded bore (5) into which a collet-like connection piece (4) au taken, the connecting piece in the axial direction, coaxially with the workpiece spindle (2), several times with slots (4.1) and approximately in the middle of the connecting piece (4) with an outer cone (4.2) and at its front end with a collar (4.3) is provided , and so is associated with tensioning and relaxing the tensioning system. 2. Automatic tensioning system according to claim 1, characterized in that the outer cone (4.2) of the collet-like connecting piece (4) with an inner cone (6.1), or in the longitudinal bore of an auxiliary mandrel (6) is a threaded bushing (6.2) is operatively connected.