JP7293501B2 - Apparatus and method for outer diameter cutting of workpiece - Google Patents

Description

The present invention relates to a method for external machining of workpieces with a geometrically undefined cutting edge. Furthermore, the invention relates to an apparatus configured for carrying out such processing methods.

From DE 10 2009 040 062 A1 an apparatus for superfinishing ring-shaped workpieces, in particular bearing rings, is known. The known device includes a device for short stroke honing having a reciprocating drive for generating reciprocating motion of the honing wheel holder. Furthermore, there are tool receptacles that are equipped to receive hard rotating tools.

A further device for mechanical finishing of surfaces on rotationally symmetrical workpieces is described in DE 102007054879 (B4). A workpiece to be machined is a bearing ring for a double-row spherical roller bearing. The tool carrier of that known machining device can be used to perform short-stroke reciprocating movements as well as long-stroke reciprocating movements using various drives.

Machining of the inner surface using a honing tool is described in DE 102011087074 (A1). The honing tool includes a grinding strip and additional stabilizing strips.

DE 28 26 169 A1 describes a grinding or honing machine for machining the bearing rings of rolling bearing rings, in which either the outer or inner circumference of the rolling bearing ring is machined. be done.

A complete production line for the manufacture of bearing components is disclosed in WO2017/028855A1. The production line includes honing machines, especially in the form of vertical honing machines.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a highly reliable external diameter machining of a workpiece with a geometrically undefined cutting edge, which is a further development of the above-described prior art.

This problem is solved according to the invention by a device for external machining of workpieces with the features of claim 1 . The problem is likewise solved by a method according to claim 6 . Aspects and advantages of the invention described below in relation to the processing method also apply to the processing apparatus as well, and vice versa.

The processing device includes a shoe, ie a workpiece holder, which is arranged to press a rotationally symmetrical workpiece against a driver, the shoe having a rotary element inserted into the workpiece. It has a holding element that is supported using rolling bearings and a rolling element that has a plastic cap provided for contact with the workpiece.

Using shoes, the workpiece, in particular the rolling bearing ring, is held during the grinding or honing process. Generally, grinding or honing methods are:
A step of providing a shoe including a retaining element and a rolling element bearing in rolling bearings on the retaining element, the rolling element comprising a metal container and a plastic cap resting on the metal container. and
providing a work piece to be machined, the work piece having a bore having a diameter matching the outer diameter of the plastic cap;
providing a processing machine, the processing machine comprising a driver configured as a rotary drive and a non-rotating tool having a geometrically undefined cutting edge;
placing the shoe in the bore of the workpiece such that the workpiece is held on the shoe and pressed against the driver at the same time;
a step of cutting the outer peripheral surface of the rotating workpiece with a non-rotating tool;
have

In particular, cutting is performed with a controlled force using a honing wheel as a non-rotating tool.

The plastic cap is preferably shaped to hold the workpiece on the rotating element without play. Due to the flexible and at the same time friction-technically advantageous properties of the raw material used for the production of plastic caps, the shoe and the tool can be separated from each other compared to solutions in which an entirely metal holder is placed on the workpiece. minimizes the risk of tilting when moving into the At the same time, a particularly uniform pressure distribution on the driver prevents parts from slipping or sticking during the machining process. Furthermore, due to the surface contact of the plastic cap against the workpiece, deformation of the workpiece during machining is essentially eliminated.

A wide variety of work pieces by providing a plurality of different rolling elements that are differentiated from each other either in terms of the sizing of metal containers and plastic caps, or only in terms of the sizing of plastic caps. The object, in particular the rolling bearing inner ring, can be finished on one and the same processing machine with minimal equipment changes.

In an advantageous form of the shoe, the metal container of the shoe has a collar against which the collar of a plastic cap provided for contact with the workpiece abuts. A wide range of axial forces can be transmitted to the ring-shaped workpiece via the collar of the metal container and the collar of the plastic cap.

The rolling bearing incorporated in the shoe is, for example, an array of multi-row ball bearings, in particular four deep groove ball bearings. A particularly uniform rotation of the rolling element is achieved during processing by means of a plurality of individual bearings. The rotating element, including the plastic cap, nearly or perfectly matches the rotational speed of the driver during the machining process. This means that during machining, in particular during honing, there is little or no sliding movement between the rolling element and the workpiece.

Embodiments of the invention are explained in more detail below with reference to the drawings.

FIG. 4 is a cross-sectional perspective view of a shoe provided for holding a rotatable work piece; FIG. 4 is a schematic cross-sectional view of machining a workpiece held with a shoe; Fig. 2 is a cross-sectional view of the metal container of the shoe; It is a perspective view of a metal container. Fig. 2 is a cross-sectional view of the plastic cap of the shoe; FIG. 3 is a perspective view of a plastic cap;

1 to 6 show in whole or in part a device, generally referred to as shoe 1, for holding a work piece 4 during outer diameter cutting of the work piece 4 with a geometrically undefined cutting edge. show. In the present case the workpiece 4 is the inner ring of a rolling bearing. The rim of the inner ring 4 is labeled 6 and the bearing rings for the rolling elements, in particular rollers, are labeled 5. A tool 8 for machining the bearing ring 5 includes a honing wheel 9 .

The components of the shoe 1 are a holding element 2 and a rolling element 3 supported on the holding element 2 . The rotary element 3 penetrates the workpiece 4 in order to machine the ring-shaped workpiece 4 , the workpiece 4 being pressed against the driver 7 . The axis of rotation of the driver 7 is the same as the central axis of the rotating element 3 labeled M and thus the central axis of the shoe 1 as a whole. The holding element 2 forms a connecting section 10 which is located in a not shown receptacle, a disc section 11 adjoining the connecting section 10 and a bearing section 12 adjoining the disc section 11 . The rolling element 3 is supported on the bearing section 12 with the smallest diameter of all the sections 10, 11, 12 using a rolling bearing generally designated 14. FIG.

The rotating element 3 consists of a metal container 13 and a plastic cap 28 which rests on the metal container 13 . A rolling bearing 14, which supports the metal container 13 on the bearing section 12, comprises four ball bearings 15, 16, 17, 18, the inner rings of the ball bearings each labeled 19 and the outer rings of the ball bearings , 20. Between a total of eight bearing rings 19, 20, four rows of balls 21 rotate as rolling elements. Therefore, rolling bearing 14 is a four-row bearing as a whole.

The metal container 13 has a bore 23 in which the head of a screw 22 is located, centrally in the bottom of the metal container 13 labeled 24 , the screw 22 being screwed into the bearing section 12 . In normal operation of the shoe 1, a gap is formed between the head of the screw 22 and the wall of the bore 23, so that the entire rotating element 3, including the metal container 13, is free to rotate. The screw 22 has the function of a locking element, e.g. the withdrawal of a component of the rolling bearing 14 from the bearing section 12 or the construction of the rolling bearing 14 when the rolling element 3 is withdrawn from the workpiece 4 . Prevent overloading of elements.

A cylindrical section 25 is connected to the bottom 24 of the metal container 13 , and a chamfer 33 is formed on the outer peripheral surface of the metal container 13 between the bottom 24 and the cylindrical section 25 . On the open front side of the metal container 13, opposite the bottom 24, the metal container 13 has a radially outwardly directed collar 26 or flange. Between the front face of disc section 11, labeled 27, and collar 26, a gap is formed during normal operation of shoe 1. FIG. The outer diameter of the collar 26 corresponds to the outer diameter of the disc section 11 in this embodiment. The wall thickness of cylindrical section 25 is labeled _WM in FIG.

A plastic cap 28 resting on the metal container 13 is shown in detail in FIGS. The bottom of the plastic cap 28 is labeled 29 and the cylindrical section directly surrounding the metal container 13 when assembled together is labeled 30 . A chamfer 31 is formed between the bottom 29 and the cylindrical section 30 . On the open front side of the plastic cap 28 there is a collar 32 which abuts against the collar 26 of the metal container 13 in the fully installed state. The outer diameter of collar 32 matches the outer diameter of collar 26 . The wall thickness, labeled _WK , of the cylindrical section 30 of the plastic cap 28 is less than half the wall thickness _WM of the metal container 13 . During operation of the shoe 1 , if an axial force is exerted in the direction from the rolling element 3 to the disc section 11 , this force is transmitted from the outer ring 20 via the rolling bodies 21 to the inner ring 19 . The individual inner rings 19 of the ball bearings 15, 16, 17, 18 are adjacent to each other. A displacement of the inner ring 19 of the ball bearing 15 closest to the connecting section 10 is prevented in the bearing section 12 by the ring-shaped surrounding abutment surface 34 . Overall, the rolling bearing 14 extends axially, ie lengthwise of the central axis M, and exceeds half the length of the multi-piece constructed rolling element 3 measured in the same direction.

REFERENCE SIGNS LIST 1 shoe 2 holding element 3 rolling element 4 workpiece, outer ring 5 bearing ring 6 lip 7 driver 8 tool 9 honing wheel 10 connecting section 11 disc section 12 bearing section 13 metal container 14 rolling bearing array 15 ball bearing 16 ball bearing 17 Ball bearing 18 Ball bearing 19 Inner ring 20 Outer ring 21 Ball 22 Screw 23 Bore 24 Metal container bottom 25 Metal container cylindrical section 26 Metal container collar 27 Disc section front surface 28 Plastic cap 29 Plastic cap bottom 30 Plastic cap 31 Chamfered portion of plastic cap 32 Collar of plastic cap 33 Chamfered portion of metal container 34 Abutment surface M Center axis W _M Wall thickness of metal container W _K Wall thickness of plastic cap

Claims (7)

Apparatus for outer diameter cutting of a workpiece (4) with a geometrically undefined cutting edge, for pressing a rotationally symmetrical workpiece (4) against a driver (7) a holding element comprising a shoe (1) configured, said shoe (1) being supported by means of a rolling bearing (14) of a rolling element (3) inserted into said workpiece (4) (2), said rotating element (3) having a plastic cap (28) provided for contact with said workpiece (4). 2. A device according to claim 1, characterized in that the plastic cap (28) rests on a rotatable metal container (13) by means of the rolling bearing (14). The metal container (13) has a collar (26) against which the collar (32) of the plastic cap (28) provided for contact with the workpiece (4) abuts, 3. Apparatus according to claim 2. 4. Device according to any one of the preceding claims, characterized in that the rolling bearing (14) is constructed as a multi-row ball bearing. 5. A device according to claim 4, characterized in that said rolling bearing (14) comprises four deep groove ball bearings (15, 16, 17, 18). A method for outer diameter machining of a workpiece (4) with a geometrically undefined cutting edge, comprising:
A step of providing a shoe (1) comprising a retaining element (2) and a rolling element (3) rollingly bearing mounted on said retaining element (2), said rolling element (3) comprising , a metal container (13) and a plastic cap (28) placed on the metal container (13);
providing a work piece (4) to be processed, said work piece (4) having a bore having a diameter matching the outer diameter of said plastic cap (28);
Providing a processing machine, said processing machine comprising a driver (7) configured as a rotary drive and non-rotating tools (8, 9) with geometrically undefined cutting edges. comprising a step;
With the shoe (1) in the bore of the work piece (4), the work piece (4) is held on the shoe (1) and simultaneously pressed against the driver (7). a step of installing as
a step of cutting the outer peripheral surface of the rotating workpiece (4) with the non-rotating tools (8, 9) ;
A method. 7. A method according to claim 6, characterized in that the cutting is carried out with a controlled force using a honing wheel (9) as tool.

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