EP3319756B1 - Pressure shoe comprising an expansion chamber - Google Patents

Description

The present invention relates to a pressure shoe having a pressing surface for directly pressing finishing tape to a radial peripheral surface of a rotating workpiece portion during finish machining.

A pressure shoe with the aforementioned features is made EP 0 802 017 A1 known, wherein the Andrückschuh is provided for processing a lying between the collar surfaces peripheral surface of the workpiece section. In order for the finishing belt lying between the pressure shoe and the workpiece to abut at any time on the rounded transitions between the peripheral surface and the lateral collar surfaces during the axial relative movement between the pressure shoe and the workpiece, two expansion chambers to be considered as expansion elements are proposed in the region of the transitions on the pressure shoe. The two expansion chambers are acted upon by a common line during finishing machining with a fluid. The fluid flows back and forth between the two expansion chambers during finish machining due to the driven relative axial movement between the pressure shoe and the workpiece, so that the expansion chambers expand in an oscillating manner. This ensures that the finishing tape is applied at all times in the transition areas between the peripheral surface and collar surfaces and on the collar surfaces. A targeted influence on the shape of the waistband or the transition areas between collar and peripheral surface is not intended.

There is a desire that during finish machining, the shape of the radial peripheral surface of the workpiece section to be machined can be specifically influenced, in particular with regard to crowning and / or out-of-roundness.

Another Andrückschuh, which forms the preamble of claim 1, is made WO 2008 / 113,925 A1 known, wherein the expansion elements are formed by cylinders, with which in each case a pressure element can be selectively acted upon in the direction of the peripheral surface with pressure via a piston located in the respective cylinder. Since the cylinder piston units are arranged one behind the other in the circumferential direction, with such a pressure shoe only the targeted generation or removal of an ovality of a peripheral surface workpiece is possible.

Out DE 196 50 155 C1 In addition, a pressing device is known in which a clamping device designed as a shell is pivotally mounted. The shell can be pivoted in response to a measured diameter by means of a piston, whereby the shell pushes the finishing tape on one side of the pivot axis of the shell stronger to the workpiece than on the opposite side of the pivot axis, so that the conicity of the workpiece surface is selectively influenced.

It is therefore an object of the present invention to at least partially solve the problems described with reference to the prior art, and in particular to provide an alternative pressure shoe and a method for operating a finish processing device with which the shape of the radial peripheral surface of the workpiece section to be machined can be specifically influenced , wherein it is particularly desirable that different profile shapes of the peripheral surface can be achieved with exactly one Andrückschuh.

This object is achieved by a pressure shoe and a method having the features of the independent claims. Advantageous developments of the pressure shoe and the method are given in the dependent claims and in the description.

The problem is solved in particular by a pressure shoe with the features mentioned above, wherein the plurality of expansion elements are individually and independently radially expandable under deformation of the pressure surface in the direction of the peripheral surface of the workpiece portion, so that in the finish machining the shape of the peripheral surface of the workpiece section targeted different expansion of distributed over the pressing surface expansion elements can be influenced.

It is therefore envisaged that the expansion elements can be supplied with energy independently of each other so that they can deform individually in the axial direction. The expansion elements can in particular be expanded in the radial direction mechanically, electromechanically, thermally, hydraulically or in another suitable manner. Due to the expansion, the pressure surface is deformed.

According to the invention, each expansion element is formed by an expansion chamber which is in each case connected individually to a line leading out of the pressure shoe and is expandable under pressure of the fluid radially under deformation of the pressure surface in the direction of the circumferential surface of the workpiece section. While the expansion element will be described in more detail below with respect to the fluid expandable expansion chamber, it is not intended that the teachings be limited to expansion chambers.

It is inventively provided that a plurality of independently expandable expansion chambers are provided, with which the profile of the integrally continuous pressure surface can be changed by deformation in the radial direction. It can thus be achieved that the shape of the pressing band of the pressure shoe pressing the finishing belt against the radial peripheral surface can be changed at least locally, which results in that the pressure of the finishing belt acting on the peripheral surface can be locally influenced. It is thus possible to predetermine the distribution of the pressure over the pressing surface, whereby the shape of the workpiece section to be machined, which can be achieved by the finish machining, can be influenced.

The pressure shoe is used in particular in a finish processing device which, in addition to the pressure shoe, comprises a rotary drive for the workpiece to be machined, an oscillation drive for generating an oscillating relative movement in the workpiece longitudinal direction between the workpiece and the pressure shoe and a finishing belt between the pressure surface and the radial peripheral surface of the pressure shoe , Thus, during the rotational movement of the workpiece, the pressure shoe can oscillate in the axial direction to press the finishing belt against the peripheral surface of the workpiece. In particular, the finish processing device also comprises a control unit for carrying out the method according to the invention.

The pressing surface of the pressure shoe is in particular that surface in the form of a surface completely formed partial ring, which during machining radially inwardly in the direction of the workpiece section to be machined is directed. The partial annular surface essentially has a radius which corresponds to the radius of the workpiece section to be machined. A (local) deviation from this radius can be achieved by pressurizing the expansion chambers.

The expansion chambers are thus formed in particular so within the Andrückschuhs that when pressure is applied, the pressing surface of the Andrückschuhs is deformed in the radial direction in the region of the respective expansion chamber. From the pressure-free rest position, the expansion chamber expands under the action of a fluid in the radial direction by at least two microns, preferably at least 5 microns, wherein the maximum expansion of the expansion chamber or the deformation of the pressure surface in the radial direction is at most 50 microns, preferably at most 30 .mu.m.

If the plurality, in particular at least two, preferably at least five expansion chambers are each connected to a line led out of the pressure shoe, the expansion chambers can be acted upon independently of one another, in particular with different pressures, so that the expansion chambers expand to different degrees in the radial direction and thus the pressure surface locally deformed differently strong.

In order to be able to influence the crowning or the conicity of the workpiece section to be machined in a targeted manner, provision can be made for the plurality of expansion chambers to extend parallel to one another along the pressing surface of the pressure shoe in the circumferential direction. Preferably, at least five expansion chambers arranged side by side in the axial direction are provided which run parallel to each other over the same length in the circumferential direction. The pressing surface is in particular uniformly deformed along the respective expansion chamber. The Andrückschuh points so in the area of the expanded expansion chamber the same or a smaller radius than before the expansion.

In order to be able to influence the out-of-roundness of the workpiece section in a targeted manner, provision can be made for the plurality of expansion chambers to extend parallel to one another along the pressing surface of the pressure shoe in the axial direction. The preferred at least seven expansion chambers are arranged in the circumferential direction next to each other and extend over the same length along the pressing surface.

The object is also achieved by a method for operating a finish processing device according to claim 5.

In particular, when pressurized and / or the volume of the fluid is detected, so that the size of the expansion of the expansion chamber can be closed in the radial direction. In this context, it may in particular be provided that a control unit is provided, which is given a size of the radial expansion and by regulating the pressure in the expansion chamber and / or the volume in the expansion chamber sets the predetermined radial expansion of the respective expansion chamber.

The fluid is in particular a liquid or a gas.

According to the invention, all expansion chambers are acted upon independently of one another by a fluid, so that the expansion chambers expand to different degrees in the radial direction. In particular, the expansion chambers are so charged with fluid that the outer expansion chambers experience the greatest radial expansion and the inner expansion chambers the least radial expansion.

In this connection, it is preferable that the expansion of the at least one expansion chamber is kept constant during finish machining. This is particularly preferred when the expansion chambers in the circumferential direction parallel to each other and thus the crown or taper of the workpiece to be machined section is determined by the expansion of the expansion chambers. In particular, it can be monitored whether the pressure and / or the volume of the fluid in the expansion chamber corresponds to the desired values, it being possible to readjust in the event of deviations.

In particular, it is provided that the expansion of adjacent expansion chambers is different, so that a achievable by the finish machining shape of the peripheral surface of the workpiece section to be machined is predetermined by the different expansion.

In particular, when the expansion chambers extend in the axial direction for influencing the out-of-roundness of the workpiece section to be machined, it can be provided that the expansion of each expansion chamber is changed in each case during the finish machining. To the desired runout to specify a shape, in this case it is provided in particular that the expansion of each expansion chamber is changed in dependence on the rotational position of the workpiece section. The expansion of the expansion chambers is controlled so that when a predetermined circumferential location of an expansion chamber, the radial expansion of this expansion chamber is always minimal, while investing a staggered circumferential location of the expansion chambers, the expansion chambers are maximally expanded. The expansion of the expansion chambers is carried out in such a way that a low abzutragende circumferential location is acted upon only by a small pressure through the respective expansion chamber, while a more abzutragende peripheral point is acted upon in each case with a larger pressure from the respective expansion chamber. It is understood that a finishing belt is always arranged between the pressing surface of the pressure shoe and the peripheral surface of the workpiece section to be machined during machining.

In particular, when the plurality of expansion chambers extend in the circumferential direction, it may be provided for selectively influencing the crowning or conicity of the workpiece section to be machined that the expansion of each expansion chamber is changed depending on the axial relative position between Andrückschuh and workpiece section. This ensures that the pressure surface is adapted to the crowning in the axial relative movement.

Fig. 1:

einen Andrückschuh und ein Werkstückabschnitt,

Fig. 2:

den Andrückschuh im Längsschnitt,

Fig. 3:

einen Querschnitt durch Expansionskammern des Andrückschuhs,

Fig. 4:

einen Querschnitt durch eine weitere Ausführungsform der Expansionskammern und

Fig. 5 bis 8:

ein Werkstückabschnitt während der Finishbearbeitung zur gezielten Erzeugung einer Unrundheit.

The invention and the technical environment are described below with reference to the figures, wherein it should be noted that the figures show preferred embodiments of the invention. It show schematically

Fig. 1:

a pressure shoe and a workpiece section,

Fig. 2:

the pressure shoe in longitudinal section,

3:

a cross section through expansion chambers of the Andrückschuhs,

4:

a cross-section through a further embodiment of the expansion chambers and

5 to 8:

a workpiece portion during finish machining for the purpose of producing an out-of-roundness.

Fig. 1 shows a Andrückschuh 1 with a radially inwardly directed, part-ring-shaped Andrückfläche 2. In the Andrückschuh 1, the expansion elements are designed as indicated expansion chambers 5. The expansion chambers 5 are arranged side by side in the axial direction 8 and extend in the circumferential direction 7 parallel to each other.

During finish machining, a finishing belt (not shown) is arranged between the pressure surface 2 and a radial peripheral surface 3 of an only indicated workpiece section 4. During finish machining, the workpiece section 4 rotates about an axis of rotation, while the workpiece section 4 and the pressure shoe 1 oscillate relative to each other in the axial direction 8, wherein the finishing belt, not shown, of the Andrückfläche 2 of the Andrückschuhs 1 for machining on the radial peripheral surface 3 of the workpiece section 4 is pressed.

From the in Fig. 2 illustrated longitudinal section through the Andrückschuh 1 in the region of an expansion chamber 5 is clear that each expansion chamber 5 is individually connected to an outgoing from the Andrückschuh 1 line 6, so that the expansion chambers 5 can be acted upon independently of each other with a fluid. If the expansion chamber 5 is acted upon by a fluid, the expansion chamber 5 expands with its Since the expansion chambers 5 are independently expandable, the profile of the pressing surface 2 along the axial direction 8 is adjustable, so that the crown of the workpiece portion 4 can be selectively influenced.

In Fig. 3 is a cross section through two expansion chambers 5, wherein only the left expansion chamber 5 is acted upon by a fluid, so that the expansion chamber 5 is expanded in the radial direction 9.

An alternative embodiment of the expansion chambers 5 is in Fig. 4 shown. The expansion chambers 5 are bellows-shaped in their cross-section, so that a larger expansion in the radial direction 9 can be achieved. Also in Fig. 4 only the left expansion chamber 5 is acted upon by a fluid.

Alternatively it can be provided that the expansion chambers 5 extend in the axial direction 8 parallel to each other and are arranged side by side in the circumferential direction 7. With such an arrangement of the expansion chambers 5, the out-of-roundness of the circumferential surface 3 of the workpiece section 4 to be machined can be influenced in a targeted manner.

The application of force to the circumferential surface 3 of the workpiece section 4 by the expansion chambers 5 of the pressure shoe 1 in such a targeted processing of the out-of-roundness is in Fig. 5 to 8 shown. In cross-section, the workpiece section 4 is egg-shaped here.

While at the in Fig. 5 When all the expansion chambers 5 are maximally expanded, the expansion of each individual expansion chamber 5 is adapted to the desired runout during the rotation of the workpiece section 4, wherein F _{0 is} greater than F ₁ and F _{1 is} greater than F ₂ . So is in Fig. 6 the expansion of the expansion chambers 5 after a rotation of 45 ° shown in Fig. 7 after a rotation of 90 ° and in Fig. 8 after a rotation of 135 °.

For example, the expansion of the upper expansion chamber 5 of the right Andrückschuhs 1 in a rotation of 45 ° ( Fig. 6 ) and increases until it reaches a rotation angle of 135 ° ( Fig. 8 ) back to.

The expansion of the upper expansion chamber 5 of the left Andrückschuhs 1, however, is initially at the rotation of 0 ° to 90 ° maximum and is slightly reduced until reaching the rotation angle of 135 °.

The present invention has the advantage that the shape of a circumferential surface 3 of a workpiece section 4 can be influenced in a targeted manner by finish machining with the pressure shoe 1.

LIST OF REFERENCE NUMBERS

1

presser

2

pressing surface

3

peripheral surface

4

Workpiece portion

5

expansion chamber

6

management

7

circumferentially

8th

axial direction

9

radial direction

Claims (10)

1. A pressure shoe (1) comprising a press surface (2) for directly pressing finishing tape onto a radial circumferential surface (3) of a rotating workpiece section (4) during a finishing process, a plurality of elements, wherein the plurality of elements can be in each case pressurized individually and independently of one another in the direction of the circumferential surface (3) of the workpiece section (4), so that during the finishing process, the shape of the circumferential surface (3) of the workpiece section can be influenced in a targeted manner by means of different pressurization of the elements distributed over the press surface (2), characterized in that each element is formed by an expansion chamber (5), which is in each case connected individually to a line (6) leading out of the pressure shoe (1) and in each case can be expanded radially under pressurization of the fluid whilst deforming the integrally cohesive press surface (2) in the direction of the circumferential surface (3) of the workpiece section (4).
2. The pressure shoe (1) according to Claim 1, wherein the plurality of expansion chambers (5) run parallel to one another in the circumferential direction (7) along the press surface (2) of the pressure shoe (1).
3. The pressure shoe (1) according to Claim 1, wherein the plurality of expansion chambers (5) run parallel to one another in the axial direction (8) along the press surface (2) of the pressure shoe (1).
4. The pressure shoe (1) according to one of the preceding claims, wherein the expansion of the expansion chambers (5) in the radial direction (9) is at most 50 µm.
5. A method for operating a finishing device with a pressure shoe (1) according to one of the preceding claims, comprising at least the following steps:

   - pressing a finishing tape onto the radial circumferential surface (3) of the workpiece section (4) to be processed, using the pressure shoe (1),

   - expanding at least one of the plurality of expansion chambers (5), so that the expansion chambers (5) deforms the press surface (2) in the radial direction.
6. The method according to Claim 5, wherein the expansion of the at least one expansion chamber (5) is kept constant during the finishing process.
7. The method according to one of Claims 5 or 6, wherein the expansion of adjacent expansion chambers (5) is different.
8. The method according to Claim 7, wherein the expansion of each expansion chamber (5) is changed in each case during the finishing process.
9. The method according to Claim 8, wherein the expansion of each expansion chamber (5) is changed as a function of the rotational position of the workpiece section (4) .
10. The method according to Claim 7 or 8, wherein the expansion of each expansion chamber (5) is changed as a function of the relative axial position between pressure shoe (1) and workpiece section (4).

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