GB2032313A

GB2032313A - Method and apparatus for the removal of swarf and oil from a workpiece

Info

Publication number: GB2032313A
Application number: GB7929465A
Authority: GB
Original assignee: Hurth Verwaltungs GmbH
Current assignee: Hurth Verwaltungs GmbH
Priority date: 1978-10-21
Filing date: 1979-08-23
Publication date: 1980-05-08
Also published as: FR2439062A1; IT1206976B; GB2032313B; IT7950083A0; DE2845866A1

Abstract

To remove swart and oil from a gearwheel 4 after machining, e.g. deburring, the machining tool is disengaged and the gearwheel is spun rapidly for a short time immediately after machining and while still mounted in the holding means 12, 13 used for machining, by a separate fast drive 19 with a motor 23. A one-way clutch 40 is provided to permit the slower rotation of the gearwheel during machining. The fast rotation is opposite to that during machining. <IMAGE>

Description

SPECIFICATION Method and apparatus for the removal of swarf and oil from a workpiece The invention relates to a method for the removal of swarf and oil from a workpiece, more particularly a gearwheel or the like, after a machining process, for example after the mechanised deburring of the tooth end edges, and to apparatus for performing the method.

In the large-scale batch production of gearwheels and similar workpieces the various machine tools are interconnected by means which supply the workpieces to the machines, remove them afterthe appropriate machining operation and convey them to the next machine. The oil dripping off the workpieces and the swarf which drops off must be collected in separate devices if the production places are not to become dirty. Furthermore, the swarf must be removed from the workpieces before these can be supplied to the next machine if faults and damage in automatic clamping are to be avoided. To this end separate stations are provided between the machines for cleaning the workpieces.The loading and unloading devices required for this have a complexity similar to that of the machines and the times required for supplying, clamping and removing the workpieces prolong the passage thereof.

It is therefore the object of the invention to provide a very simple method and apparatusforthe removal of swarf and oil, to permit adequate cleaning of the workpieces without any additional expenditure of time.

The present invention provides a method of machining a workpiece in which, immediately after machining, the workpiece and machining tool are disengaged and the workpiece, remaining in the holding means used in the machining, is rotated for a short time ata speed sufficient to throw off oil and swarf.

In accordance with the invention, directly after the machining operation and with the same clamping in the machine end the workpiece, when it has ceased to be in mesh with the tool, is driven at a speed which is higher than that of the machining operation while oil and swarf are thrown off centrifugally.

Apparatus suitable far this process includes a driving device which acts on a driver of the workpiece holding means in the machine and thus rotatingly drives the workpiece in order to throw off oil and swarf. Preferably, means are provided for decelerating the workpiece, and such means can be combined in a simple manner with the motor of the driving device, so that after the centrifuging operation the workpiece can be rapidly stopped in order to minimize the machining times. A sprag clutch or the like is provided to disconnect the driving device from the driver of the workpiece holding means during the machining operation.

The invention will be explained hereinbelow by reference to an exemplified embodiment illustrated in the accompanying drawings, in which: Figure 7shows in diagrammatic form a machine for deburring the edges of gearwheels, on which the invention can be performed, and Figure 2 shows a longitudinal section through apparatus according to the invention.

Figure 1 shows in diagrammatic form a machine frame 1 on which a tool 3 is pivotably supported on a tool carrier 2 so that for the machining operation it can be brought into mesh with a workpiece 4, a gearwheel, which is in the working position 5. In Figure 1 the tool is in an inoperative position 6. The workpiece can be moved by a conveying device 10 into the aforementioned working position. The conveying device is arranged so that one or more workpieces4' will be in awaiting position 8 between the working position 5 and a loading position 7.

When a workpiece 4to be machined is in the working position 5 the tool 3 will be pivoted into a working position 9 in which it meshes with the workpiece. The tool is rotatingly driven by a motor (not shown) via a work spindle, also not shown.

Accordingly, the workpiece 4 which meshes with the tool 3 is driven. During the rolling motion the cutting edges of the tool remove the burr from the ends of the workpiece teeth and/or chamfer the tooth ends.

Such tools are known for example as disclosed in the German Patent Specification 23 19 060 and need not be described in this context. When theworkpiece has been machined the tool 3 pivots back into the operative position 6. As soon as the tool and the workpiece are disengaged the workpiece is driven, by the apparatus according to the invention, at a higher speed in order to throw off any adhering swarf and oil from the workpiece.

This apparatus is shown in Figure 2. The workpiece 4, held on a manderel 16 on a machine table 1'1 or the like, is clamped between centres 13,15 of two tailstocks 12, in known manner. Iftheworkpieceis suitably shaped it can be directly held between centres. Thetailstocks 12, 13 are slidably and locably arranged on the machine table 11 or the like by known means. One tailstock centre 15 is constructed as driver and is driveable.

A carrier 20 of a driving device 19 is mounted by screwfasteners 21 and T-slot blocks (not shown) on the machine table 11 or the like, adjacenttothe tailstock 14, and is in flush alignment with the tailstock 14 by means of at least one key 22. A driving motor 23 is retained on the carrier 20 in a slot 27 via a holding ring 24 and by means of screwfasteners 25, 26. A bush 29, supported in the holding ring 24, is fixedly mounted on the output shaft 28 of the motor and at its free end supports a toothed belt pulley 30.

This is coupled via a toothed belt 31 to a second toothed belt pulley 32 which is fixedly mounted on the free end of a sleeve 33 which is rotatably supported in the carrier. The bore of the sleeve is provided with a splined internal profile in which a drive shaft 34 with a spline section 35 is nonrotationally but axially slidably guided. The drive shaft is coupled to the spindle 36 of the driver 15 by known means, for example by a press fit 37. The spindle and drive shaft 34 can of course also be constructed in integral form. The belt drive 29 to 34 is covered by a cover plate 39.

To throw off swarf and oil from the workpiece 4, the spindle 36 is rotated by the motor 23 via the belt drive 29 to 33 and by the drive shaft 34. As a rule the standard speed of 2800 revlmin of the motor is sufficient, applied to the workpiece with a 1:1 transmission ratio of the belt drive. This speed is several times the speed of the machining process, in which the workpiece rotates at a maximum speed of only 500 rev/min. By selecting a different belt transmission ratio is of course possible to obtain an even higher rotational speed for centrifuging.

The belt drive used in the present example can of course be replaced by other power transmission elements, for example gearwheels or roller chains.

A screwfastener 36, by means of which the centre distance of the two belt pulleys 30,32 can be altered by sliding the holding ring 24 in the slot 27 of the carrier 20, is provided fortensioning and retensioning of the toothed belt.

Afew seconds are sufficient for the centrifuging operation. It is convenient for the workpiece to be decelerated thereafter in order to shorten the machining time. This can be achieved, for example by means of a brake (not shown) which is mounted on the drive shaft, or more simply by the use of a brake motor for the driving motor 23.

As already mentioned, the workpiece 4 is driven by by the tool 3 during the machining operation and a sprag clutch 40 is therefore provided between the sleeve 33 and the toothed belt pulley 32. By means of this sprag clutch the rotating motion of the workpiece is not transmitted to the belt drive and the motor. It therefore follows that during centrifuging the direction of rotation of the workpiece 4 must be opposite to the direction of rotation of the machining process. To change the workpiece the quill 45, in which the spindle 36 is supported, is hydraulically shifted in known manner. To this end the tailstock 15 incorporates a jack 41 in which a piston 42 can slide between two limiting positions. Hydraulic oil is selectively conducted via ducts (not shown) into the cylinder chambers 43, 44. The spline section 35 of the drive shaft 34 slides in the internal splined section of the sleeve 33 when the quill is shifted.

Claims

1. A method of machining a workpiece in which, immediately after machining, the workpiece and machining tool are disengaged and the workpiece, remaining in the holding means used in the machining, is rotated for a short time at a speed sufficient to throw off oil and swarf.

2. A method as claimed in claim 1 in which the workpiece is a gear wheel.

3. A method as claimed in claim 2 in which the machining comprises deburring the gear tooth ends, the said speed being several times that at which the deburring is performed.

4. Apparatus for machining a gearwheel or like workpiece by means of a rotary tool that meshes with the workpiece, including first driving means for rotating the tool and workpiece in mesh for machining the workpiece, and further driving means for rotating the workpiece alone at a speed substantially higher than that of the first driving means.

5. A method for the removal of swarf and oil from a workpiece, more particularly a gearwheel or the like, after a machining process, for example after the mechanised deburring of the tooth end edges, characterised in that swarf and oil are removed directly after the machining process, and to this end the workpiece remains in the same clamping means on the machine but is disengaged from the machining tool and for a short time is driven at a speed which is higher than that of the machining operation whereby swarf and oil are thrown off.

6. Apparatus for performing the method claimed in claim 5, in which the workpiece is rotatably retained between centres or the like, and the workpiece is rotatably driven by a gearwheel-like tool which meshes with the said workpiece during machining, characterised in that one of the two workpiece centres or the like is constructed as a driver which, when the workpiece and the tool are disengaged, can be rotatably driven by its own driving device at a speed which is multiple of the workpiece speed during machining.

7. Apparatus according to claim 6, characterised by the provision of means for decelerating the workpiece when it rotates at high speed.

8. Apparatus according to claim 7, characterised in that the driving device incorporates a brake motor.

9. Apparatus according to any of claims 6to 8, characterised in that during the machining operation the driving device is disconnected via a sprag clutch or the like from the driver which will then be driven via the workpiece by the tool.

10. Apparatus for machining gear wheels, sub stantially as herein described with reference to the accompanying drawings.

11. A method of machining gear wheels substantially as herein described with reference to the accompanying drawings.