Rolling tool

Abstract

Disclosed is a rolling tool which serves for workingin particular rolling smoothan inner lateral surface of a cylindrical clearance. For this purpose, the rolling tool has at least one rolling body, which is held in the rotatably drivable rolling tool, and can be taken along by said tool on a peripheral path along the inner lateral surface. The at least one rolling body is inserted into a radial clearance in the rolling tool and can be subjected to a pressurized fluid from the inside to the outside along the radial clearance. The fluid is an aerosol. The aerosol is a fluid mixed with gas and serves for hydrostatic bearing and lubrication.

Claims

1. A rotatable rolling tool for working a cylindrical clearance comprising at least one rolling body which is held in the rolling tool and is driven by the rolling tool, the at least one rolling body is inserted into at least one radial clearance of the rolling tool and is subjected to a pressurized fluid along the clearance to an outside, and a rapid air-vent valve by which an application of the pressurized fluid to the at least one rolling body is connected and disconnected, wherein the pressurized fluid is a cooling lubricant mixed with air, and wherein the application of the pressurized fluid to the rolling body is relieved via the rapid air-vent valve.

2. The rolling tool according to claim 1, wherein the at least one rolling body is a ball.

3. The rolling tool according to claim 2, wherein each of the at least one radial clearance has a seat ring which, together with the ball, forms a valve for the cooling lubricant mixed with air, wherein the valve is opened when the ball contacts the cylindrical clearance.

4. The rolling tool according to claim 3, wherein the radial at least one clearance and the seat ring are formed at a sleeve.

5. The rolling tool according to claim 4, wherein the sleeve is inserted in the rolling tool and is held by a screwed hold-down in the rolling tool.

6. The rolling tool according to claim 4, wherein a nozzle body and the at least one rolling body are arranged in one plane.

7. The rolling tool according to claim 2, wherein two or three radial clearances including two or three respective balls are evenly distributed on the periphery of a rolling tool.

8. The rolling tool according to claim 1, further comprising a cleaning nozzle adapted to be supplied with the cooling lubricant mixed with air and arranged at an outer periphery of the rolling tool, wherein the cooling lubricant mixed with air is an aerosol.

9. The rolling tool according to claim 8, wherein the cleaning nozzle is inclined against a direction of rotation of the rolling tool.

10. The rolling tool according to claim 8, wherein the cleaning nozzle is inclined against a feed direction of the rolling tool.

11. The rolling tool according claim 8, wherein the cleaning nozzle is in a form of a bore in a nozzle body extending approximately radially from a longitudinal passage to a periphery of the nozzle body and wherein a radial passage arranged inside the nozzle body communicates the longitudinal passage with the bore.

12. The rolling tool according to claim 8, wherein the supply of aerosol to the cleaning nozzle can be connected and disconnected via the rapid air-vent valve.

13. The rolling tool according to claim 8, wherein the rapid air-vent valve can be switched in response to a speed of rotation of the rolling tool.

14. The rolling tool according to claim 1, wherein the cylindrical clearance is a connecting rod eye.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Hereinafter different embodiments of the invention are described in detail by way of the figures which show in:

(2) FIG. 1 a rolling machine comprising a first embodiment of a rolling tool according to the invention partly in lateral section and partly in a schematic representation;

(3) FIG. 2 a second embodiment of a rolling tool according to the invention in a perspective view;

(4) FIG. 3 a third embodiment of a rolling tool according to the invention in a perspective view; and

(5) FIG. 4 the third embodiment of a rolling tool according to the invention in a partly cut view.

DETAILED DESCRIPTION OF THE INVENTION

(6) FIG. 1 shows a rolling machine partly in lateral section and partly in a schematic representation. The rolling machine comprises a rolling tool 1 adapted to be rotationally driven vis--vis a stationary housing 3.

(7) A portion 5 of the tool 1 is introduced in portions into a connecting rod eye 2 of a connecting rod 4. The connecting rod 4 is fastened to an acceptance 6 and thereby can be translationally displaced vis--vis the tool 1 (according to the double arrow).

(8) The portion 5 of the tool 1 being introduced into the connecting rod eye 2 is substantially cylindrical. Two opposing radially extending sleeves 8a, 8b are inserted in the portion 5. At the radial outer end portions thereof seat rings are formed by respective restrictions (not shown in detail in FIG. 1). Balls 10a, 10b are accommodated largely inside the sleeves 8a, 8b having an interior defining a clearance 9, wherein there are substantially two different positions of the balls 10a, 10b: in an idling position (not shown) the balls 10a, 10b are in sealing contact with the respective seat ring 11, 15, while in a working position they are lifted over the inner wall of the connecting rod eye 2 off the respective seat ring and are urged inwardly in the direction of a longitudinal axis 14 of the tool 1. This position is shown in FIG. 1.

(9) From inside the sleeves 8a, 8b are subjected to pressurized aerosol via a longitudinal passage 12 extending inside the tool along the longitudinal axis 14. The aerosol is a mixture of ambient air and cooling lubricant. For the production thereof ambient air is sucked and compressed by a compressor 16 and is conveyed via an air-flow meter 18 to a mixing unit 20. In parallel to the ambient air, cooling lubricant is conveyed to the mixing unit 20 by a lubricant unit 22. The lubricant unit 22 includes a reservoir and a pump. In the mixing unit 20 the aerosol is produced which is aerated cooling lubricant.

(10) The aerosol is conveyed via a programmable circuit 24 to a rotary feed 26. The circuit 24 is formed by a non-return valve and the rotary feed 26 connects a stationary aerosol line 28 including a rotating aerosol line 30. The latter finally opens into the longitudinal passage 12 which in turn opens into the two sleeves 8a, 8b.

(11) With a so called ball burnishing of the connecting rod eye 2 the circuit 24 is opened so that the aerosol urges the balls 10a, 10b radially outwardly e.g. at a pressure of 55 bar with a force of approx. 150 Nm each. Since the balls 10a, 10b are lifted off their respective seat ring by getting into contact with the connecting rod eye 2, a respective annular gap is formed through which equally aerosol penetrates into the working zone. By rotation of a drive which is transferred to the tool 1 via a tool holder (HSK) 7 and by the simultaneously performed linear feed of the connecting rod 4 via the acceptance 6 the balls 10a, 10b roll along helical paths through the connecting rod eye 2 with a comparatively high pressing force and smooth-roll the same.

(12) In the first embodiment according to FIG. 1, the two sleeves 8a, 8b are inserted in corresponding radial bores of the tool 1 and are glued in the same. FIG. 2 illustrates, deviating therefrom, a rolling tool 101 according to a second embodiment in a perspective view. The tool holder (HSK) 7, the longitudinal passage 12, the sleeves 8a, 8b and the balls 10a, 10b are comparable to those of the first embodiment. In FIG. 2 the longitudinal passage 12 is not shown, whereas only one sleeve 8a of the two sleeves and only one ball 10a of the two balls is shown.

(13) Deviating from the first embodiment, each of the two sleeves 8a is held via a work-holding strap or a hold-down, out of which only one hold-down 109a is shown in FIG. 2, in the respective clearance of the tool 101. The two hold-downs 109a have respective radial screwed connections and overlap the respective outer end face of the sleeve 8a so that they are positively fixedly connected to a portion 105 of the tool 101. In this case, each of the hold-downs 109a is inserted in a hole so as not to contact the connecting rod eye 2 when using the tool 101 according to the invention (cf. FIG. 2).

(14) FIG. 3 illustrates a third embodiment of a rolling tool 201 according to the invention in a perspective view. It includes a portion 205 which during roller-burnishing is moved into the smaller connecting rod eye 2 of the connecting rod 4 (cf. FIG. 1) at least in portions in a translational and rotational fashion. The two balls 10a, the two sleeves 8a and the two hold-downs 109a correspond to those of the preceding embodiments and are shown, on the one hand, at the top of FIG. 3 and are covered, on the other hand, at the bottom of FIG. 3.

(15) In addition to the preceding embodiments, at the third embodiment a cleaning nozzle 232 and a rapid air-vent valve 234 are provided. The cleaning nozzle 232 generates an aerosol jet 236 inclined by 45 in a twofold respect. Said aerosol jet is inclined, on the one hand, by 45 with respect to the feed direction 238 of the tool 201 and is inclined, on the other hand, by 45 with respect to a direction of rotation 240 (cf. FIG. 4). The cleaning nozzle 232 is supplied with the aerosol available inside the tool 201 according to the invention.

(16) When during operation of the third embodiment of the tool 201 according to the invention, on the one hand the latter is moved along the feed direction 238 into the connecting rod eye 2 (cf. FIG. 1) and, on the other hand, is driven rotatably about its longitudinal axis, for each of the ball 10a and an impinging position of the aerosol jet 236 in the connecting rod eye 2 a helical direction of motion is resulting. The reference numeral 242a denotes the direction of motion of the ball 10a and the reference numeral 244 denotes the direction of motion of the impinging position of the aerosol jet 236.

(17) The rapid air-vent valve 234 is arranged inside the tool 201 and is shown only symbolically in FIG. 3. It has a valve body adjusting against a spring in response to the speed of the tool 201. Thuswith a comparatively high speedthe rapid air-vent valve 234 can either connect the aerosol supply of the two balls 10a and of the cleaning nozzle 232 orwith comparatively low speeds and in the case of standstilldisconnect the aerosol supply and at the same time rapidly relieve the passages guiding aerosol inside the portion 205. This is performed through orifices 246.

(18) FIG. 4 illustrates the third embodiment of the tool 201 according to the invention in apartly cutend face view of its portion 205. It is visible that the cleaning nozzle 232 is in the form of a bore in an end cap of a substantially hollow-cylindrical nozzle body 248. The nozzle body 248 extends radially from the longitudinal passage 12 to the outer periphery of the portion 205. Thus a radial longitudinal axis 250 of the nozzle body 248 is resulting. As is described with reference to FIG. 3, the bore or the cleaning nozzle 232 and thus the aerosol jet 236 exiting the same are bent by 45 in a twofold respect, wherein in FIG. 4 only the bending with respect to the direction of rotation 240 is visible. By this bending also an inserted bending of 45 is resulting vis--vis the radially extending longitudinal axis 250 of the nozzle body 248. Equally along the longitudinal axis 250, a radial passage 252 through which the bore 232 is supplied with aerosol from the longitudinal passage 12 extends inside the nozzle body 248.

(19) In an operating mode, first the tool 201 is accelerated to approx. 5000 rpm and is moved (according to the feed direction 238 shown in FIG. 3) in a rapid pre-stroke into direct vicinity of the connecting rod eye 2 (cf. FIG. 1). Then a working feed (according to the feed direction 238) takes place in which it is simultaneously cleaned and roller-burnishedat a pressure of approx. 50 to 60 bars. After that, the rotary drive is disconnected and at about 2000 rpm the rapid air-vent valve 234 opens. The pressure and thus the radial forces of the balls 10a, 10b are quickly reduced and in a rapid back-stroke the tool 201 is withdrawn (against the feed direction 238) from the connecting rod eye 2 (cf. FIG. 1). Then another connecting rod 4 (cf. FIG. 1) can be moved to the tool 201.

(20) In another operating mode, at firstat approx. 6 to 8 baronly the cleaning nozzle 232 is operated in a rapid feed (according to the feed direction 238) through the connecting rod eye 2 (cf. FIG. 1). Then the speed is increased and the rapid air-vent valve 234 closes. In a subsequent working back-stroke roller-burnishing takes placeat approx. 50 to 60 bars. In this operating mode bending of the cleaning nozzle 232 and the advance of the impinging position of the aerosol jet 236 can be dispensed with.

(21) There is disclosed a rolling tool which serves for workingin particular smooth-rollingan inner lateral surface of a cylindrical clearance. For this purpose, the rolling tool has at least one rolling body which is held in the rotatably drivable rolling tool and can be driven by said tool on a peripheral path along the inner lateral surface. In this case, the at least one rolling body is inserted into a radial clearance of the rolling tool and can be subjected to pressurized fluid from the inside to the outside along the radial clearance. According to the invention, the fluid is an aerosol. The aerosol is a fluid mixed with gas and serves for hydrostatic bearing and for lubrication. In this case, the amount of fluid required is reduced vis--vis the prior arton the basis of minimal quantity lubrication (MQL).

LIST OF REFERENCE NUMERALS

(22) 1; 101; 201 Rolling tool 2 connecting rod eye 3 housing 4 connecting rod 5; 105; 205 portion 6 acceptance 7 tool holder 8a, 8b sleeve 10a, 10b ball 12 longitudinal passage 14 longitudinal axis 16 compressor 18 air-flow meter 20 mixing unit 22 lubricant unit 24 circuit 26 rotary feed 28, 30 aerosol line 109a hold-down 232 cleaning nozzle 234 rapid air-vent valve 236 aerosol jet 238 feed direction 240 direction of rotation 242a direction of motion 244 direction of motion 246 orifice 248 nozzle body 250 longitudinal axis