DE102020130004A1 - Cylindrical grinding machine with dressing unit - Google Patents

Abstract

The present invention relates to a cylindrical grinding machine for grinding a cylindrical workpiece. The cylindrical grinding machine comprises a machine bed (03) which carries a swivel table (07) on which a workpiece headstock (08) for rotating the workpiece is arranged in a fixed mountable manner and on which a tailstock (11) is arranged in a fixed manner. A first axis of rotation is defined by the work headstock (08) and the tailstock (11). The swivel table (07) can be swiveled about a swivel axis relative to the machine bed (03). The cylindrical grinding machine also includes a grinding wheel (06) that can be rotated about a second axis of rotation. The first axis of rotation and the second axis of rotation are co-located in a vertical plane, with the second axis of rotation being positioned above the first axis of rotation. A longitudinal guide (17) is used to move the grinding wheel (06) axially. The longitudinal guide (17) is arranged in the vertical plane comprising the first axis of rotation and the second axis of rotation. A dressing unit (16) serves to dress the grinding wheel (06). The dressing unit (16) is arranged in the axial direction next to the tailstock (11) on the machine bed (03) in relation to the first axis of rotation.

Description

The present invention relates to a cylindrical grinding machine for grinding a preferably rotatable workpiece. The cylindrical grinding machine is used in particular for grinding a cylindrical workpiece, for example, clamped between centers or on one side, using a rotating grinding wheel. The cylindrical grinding machine also includes a dressing unit for dressing the grinding wheel.

the DE 31 36 396 A1 shows a portal grinding machine with one or more stands and a traverse attached to the stand at the top. An infeed carriage is movably mounted on the traverse and carries a tool drive head for driving a machining tool. A workpiece set-up bench has two spaced workpiece holders between which the workpiece to be machined is kept free and is driven in rotation about its longitudinal axis. The infeed carriage can be moved transversely to the longitudinal axis of the workpiece. When machining the workpiece, the machining tool is arranged above the longitudinal axis of the workpiece. The infeed carriage can also be moved parallel to the longitudinal axis of the workpiece. The two spaced workpiece holders are formed by a work headstock fixed on a working platform and by a tailstock that can be fixed on the working platform.

The DD 7177 shows a device for fine dressing a grinding wheel. A positively guided dressing wheel that runs along and is set at an angle to the axis of rotation of the grinding wheel is moved parallel to the axis of rotation of the grinding wheel. The axis of rotation of the dressing wheel set at an angle lies in a common plane with the axis of rotation of the grinding wheel.

In the EP 3 351 344 A1 describes a cylindrical grinding machine in which a grinding wheel is guided vertically upwards while the workpiece to be machined is positioned below the grinding wheel. A rotation axis of the workpiece lies on a vertical plane on which a rotation axis of the grinding wheel is moved in the vertical direction. The axis of rotation of the workpiece can be adjusted in this vertical plane as well as transversely or at right angles to it in the thousandths of a millimeter range. A disadvantage of this cylindrical grinding machine is that, despite the arrangement of the grinding wheel over the workpiece, unwanted tilting can occur between the grinding wheel and the workpiece, so that the machining accuracy that can be achieved is limited.

Based on the prior art, the object of the present invention is to increase the machining accuracy of a cylindrical grinding machine while keeping the structural design simple. At the same time, a high level of dressing accuracy should be achievable. The dimensions of the machine should preferably be able to be designed in such a way that it only requires a small amount of space in a workshop.

The above object is achieved by a cylindrical grinding machine according to appended claim 1.

The cylindrical grinding machine according to the invention is used for grinding a workpiece. The workpiece is preferably made of metal, for example steel. Rotationally symmetrical as well as non-rotationally symmetrical workpieces can be processed with the cylindrical grinding machine. By grinding the workpiece with the cylindrical grinding machine, high demands can be met with regard to the surface to be achieved, accuracy, dimensional accuracy and freedom from twist.

The cylindrical grinding machine includes a machine bed, which is preferably attached to a main stand of the cylindrical grinding machine. The main stand forms a support for all other components of the cylindrical grinding machine. The machine bed is preferably aligned horizontally. The machine bed carries a swivel table, on which a work headstock for the rotary drive of the work piece is arranged in a fixed mountable manner. The workhead and also the swivel table are not designed to be displaced during grinding of the workpiece. In particular, the workhead is not designed to be displaced axially in the direction of an axis of the workhead during grinding of the workpiece. The work headstock is preferably permanently mounted on the swivel table.

A tailstock is also arranged in a fixed manner on the swivel table or on a lifting carriage attached to it. The tailstock is used to hold the workpiece at an axial end of the workpiece opposite the workpiece headstock. The lifting carriage can move the tailstock axially when the workpiece is to be clamped or unclamped. A first axis of rotation about which the workpiece can be rotated is defined by the workhead and the tailstock. The tailstock can preferably be moved and fixed on the swivel table in order to be able to adapt it to workpieces of different lengths.

The swivel table can be swiveled relative to the machine bed about a swivel axis aligned in a horizontal direction transverse to the first axis of rotation. This means that the workpiece clamped in the workhead can also be swiveled relative to the machine bed. Therefore, the first axis of rotation can also be pivoted within a vertical plane. The pivoting movement can preferably be fixed, so that the pivoting table cannot be pivoted, in particular during the grinding of the workpiece. If the pivoting movement is fixed, the pivoting table is preferably firmly connected to the machine bed. The pivoting table can preferably be pivoted with respect to a horizontal line, so that the pivoting table is aligned horizontally in an initial position. In this starting position, the first axis of rotation is also aligned horizontally.

The cylindrical grinding machine also includes a grinding wheel that can be rotated about a second axis of rotation for grinding the workpiece. The first axis of rotation and the second axis of rotation are arranged together in a vertical plane. The second axis of rotation is positioned above the first axis of rotation such that the grinding wheel is positioned above the workpiece. The workpiece is thus machined from above by the grinding wheel. The second axis of rotation is arranged above the first axis of rotation with respect to the vertical direction. The grinding wheel is preferably seated on a shaft, which is in particular a grinding spindle. This grinding spindle is preferably mounted in at least one, preferably in several, rotary bearings, so that it can rotate, whereby the grinding wheel also rotates and the workpiece can be ground with the grinding wheel. The second axis of rotation is preferably aligned horizontally, in particular fixed horizontally.

The cylindrical grinding machine also includes a longitudinal guide for displacing the rotatable grinding wheel axially in the direction of the second axis of rotation, i. H. for moving in the direction defined by the second axis of rotation. For this purpose, in particular, a tower, which carries the grinding wheel spindle and the grinding wheel, is shifted axially. As a result, the grinding wheel can be moved to different axial positions of the workpiece in order to grind the workpiece there in each case. The longitudinal guide is also arranged in the vertical plane comprising the first axis of rotation and the second axis of rotation. The longitudinal guide has in particular a central guide axis which is preferably arranged in the vertical plane comprising the first axis of rotation and the second axis of rotation. The longitudinal guide is designed in particular to move the grinding wheel indirectly along the second axis of rotation. The longitudinal guide is preferably designed to move the grinding wheel spindle carrying the grinding wheel or the at least one bearing supporting the grinding wheel spindle in the direction of the second axis of rotation, as a result of which the grinding wheel is indirectly moved in the direction of the second axis of rotation, i. H. is shifted on the second axis of rotation. The shaft is preferably a grinding spindle with an electric grinding wheel motor. The at least one bearing is accordingly a spindle bearing. The longitudinal guide then serves for the direct or indirect axial displacement of the grinding wheel motor in the direction of the second axis of rotation, as a result of which the grinding wheel is also displaced indirectly in the direction of the second axis of rotation. An advantage of the axial displacement of the grinding wheel motor is that the distance between the spindle bearing and the grinding wheel is constant.

The cylindrical grinding machine also includes a dressing unit for dressing the grinding wheel. The dressing unit is arranged in the axial direction next to the tailstock on the machine bed in relation to the first axis of rotation. The dressing unit is therefore preferably also arranged in the first axis of rotation, specifically next to the tailstock on the machine bed. The dressing unit is preferably mounted on the machine bed so that it can be displaced in a horizontal direction transverse to the first axis of rotation, so that it can be moved in this direction in relation to the grinding wheel; for example, to guide a dressing tool sitting on the dressing unit to the grinding wheel or to be able to choose from different dressing tools sitting on the dressing unit.

A particular advantage of the cylindrical grinding machine is that the joint arrangement of the two rotational axes and the longitudinal guide in a single vertical plane allows high machining accuracy and a compact design of the cylindrical grinding machine. In addition, the workpiece sitting on the workhead does not have to be moved in the direction of the second axis of rotation, since the grinding wheel can be moved lengthwise with the help of the longitudinal guide. The workpiece is thus firmly seated on the machine bed, which enables increased machining accuracy. By doing without a guide unit on the work headstock that can be moved during machining, deformation of this guide unit is excluded, especially with high grinding forces acting perpendicular to the axis of rotation, which means that the position of the workpiece is unchangeable during the entire grinding process, even under dynamic stress.

In preferred embodiments, the cylindrical grinding machine further includes a grinding wheel motor. The grinding wheel motor has a motor shaft coupled to the grinding wheel spindle on which the grinding wheel is fixedly mounted. The motor shaft lies in the second axis of rotation. The at least one rotary bearing for mounting the grinding wheel is formed, for example, in the grinding wheel motor. The longitudinal guide carries the grinding wheel motor together with the grinding wheel. The longitudinal guide carries the grinding wheel motor preferably indirectly.

The longitudinal guide preferably comprises two parallel guide rails which are arranged in a horizontal plane. The central guide axis runs in the middle between these two guide rails and is preferably arranged in the vertical plane comprising the first axis of rotation and the second axis of rotation. The guide rails are preferably located on the main stand of the cylindrical grinding machine.

The longitudinal guide preferably includes a first actuator, by which the longitudinal guide can be driven. The grinding wheel can thus be displaced in the direction of the second axis of rotation by the drive of the first actuator. The longitudinal guide allows the rotatable grinding wheel to be displaced by preferably at least 400 mm and more preferably at least 700 mm.

In preferred embodiments, the cylindrical grinding machine also includes a vertical guide for guiding the grinding wheel vertically. The grinding wheel can be guided up and down in the vertical direction by the vertical guide. The grinding wheel can therefore be guided to the workpiece from above with the vertical guide in order to grind the workpiece. In relation to the first axis of rotation, the grinding wheel is guided in the radial direction to the workpiece by the vertical guide. The vertical guide preferably carries the grinding wheel motor together with the grinding wheel. The longitudinal guide preferably carries the vertical guide and thus indirectly also the grinding wheel motor.

The vertical guide preferably includes a second actuator, by which the vertical guide can be driven. Thus, the grinding wheel can be shifted up and down in the vertical direction by driving the second actuator. The vertical guide allows the rotatable grinding wheel to be displaced by preferably at least 200 mm.

In preferred embodiments, the cylindrical grinder further includes a turret supported by the longitudinal guide. The tower carries the vertical guide, with the vertical guide preferably being arranged in or on the tower. The vertical guide carries the grinding wheel; in particular the grinding wheel motor with the coupled grinding wheel spindle and the grinding wheel sitting on it. The tower is arranged next to the grinding wheel in the axial direction in relation to the second axis of rotation. The tower is preferably arranged next to the dressing unit in the axial direction relative to the first axis of rotation, with the dressing unit being located between the tower and the tailstock.

The tower is preferably carried by the two guide rails on the main stand and is guided in these guide rails, which form the longitudinal guide. Preferably, the tower is slid along the longitudinal guide to move the grinding wheel.

The tower preferably has a central axis which is oriented vertically and is arranged in the axial direction next to the grinding wheel in relation to the second axis of rotation. The central axis is preferably arranged next to the dressing unit in the axial direction relative to the first axis of rotation, the dressing unit being located between the central axis and the tailstock. The middle axis preferably lies in the vertical plane comprising the first axis of rotation and the second axis of rotation.

The work headstock preferably comprises a work piece motor for driving the work piece in rotation and a work piece spindle. The workhead can be moved on the swivel table and fixed there.

The dressing unit preferably comprises a number of different dressing tools, which are arranged next to one another in a horizontal plane. Since the dressing tools are mounted on the dressing unit so that they can be displaced in a horizontal direction transversely to the first axis of rotation, one of the dressing tools can be selected for dressing in each case by such a displacement process. The plurality of dressing tools are preferably arranged next to one another in a horizontal direction transverse to the first axis of rotation.

According to a preferred embodiment, the dressing unit comprises at least one static dressing tool and at least one dynamic dressing tool, so that different dressing processes can be carried out on the grinding wheel.

In preferred embodiments, the pivoting table is on a first axis of rotation related axial first end of the swivel table pivoted in a pivot bearing relative to the machine bed. A vertical distance between an axial second end of the swivel table, which is related to the first axis of rotation, and the machine bed is defined by an adjustment element. The vertical distance between the axial second end of the swivel table, which is related to the first axis of rotation, and the machine bed is defined in particular by an adjustable length of the adjustment element. The adjusting element is preferably formed by a spindle. The adjusting element preferably includes a coarse adjustment and a fine adjustment.

The swivel table can preferably be swiveled by at least ±5° in relation to the machine bed.

In preferred embodiments, the machine bed includes a base plate on which the dressing unit, the pivot bearing and the adjustment element are attached. The base plate is preferably made of cast steel.

• 1: eine Seitenansicht einer bevorzugten Ausführungsform einer erfindungsgemäßen Rundschleifmaschine;
• 2: eine perspektivische Ansicht der in 1 gezeigten Rundschleifmaschine;
• 3: eine Detailansicht der in 1 gezeigten Rundschleifmaschine mit einem horizontal ausgerichteten Schwenktisch;
• 4: eine Detailansicht der in 1 gezeigten Rundschleifmaschine mit einem um -10° geneigten Schwenktisch;
• 5: eine Detailansicht der in 1 gezeigten Rundschleifmaschine mit einem um +6° geneigten Schwenktisch;
• 6: eine Seitenansicht der in 1 gezeigten Rundschleifmaschine während eines Abrichtvorganges; und
• 7: eine Detailansicht der in 1 gezeigten Rundschleifmaschine während eines Abrichtvorganges mit einem um -10° geneigten Schwenktisch.

Further details and developments of the invention result from the following description of a preferred embodiment of the invention, with reference to the drawing. Show it:

• 1 : a side view of a preferred embodiment of a cylindrical grinding machine according to the invention;
• 2 : a perspective view of the in 1 cylindrical grinding machine shown;
• 3 : a detailed view of the in 1 shown cylindrical grinding machine with a horizontally aligned swivel table;
• 4 : a detailed view of the in 1 Cylindrical grinding machine shown with a swivel table inclined by -10°;
• 5 : a detailed view of the in 1 Cylindrical grinding machine shown with a swivel table inclined by +6°;
• 6 : a side view of the in 1 Cylindrical grinding machine shown during a dressing process; and
• 7 : a detailed view of the in 1 Cylindrical grinding machine shown during a dressing process with a swivel table inclined by -10°.

1 shows a side view of a preferred embodiment of a cylindrical grinding machine according to the invention. The cylindrical grinding machine includes a main stand 01, which carries a tower 02 and a machine bed 03. The tower 02 carries a grinding unit 04, which is also referred to as a grinding headstock and which includes a grinding wheel motor (not shown) and a grinding wheel 06 driven by the grinding wheel motor.

A swivel table 07 is arranged on the machine bed 03, on which a workpiece headstock 08 for the rotational drive of a workpiece 09 (shown in 4 ) is fixed. In addition, a tailstock 11 is arranged on the swivel table 07 so that it can be fixed. The distance between the tailstock 11 and the workhead 08 can be changed. The workpiece 09 can be clamped between the workhead 08 and the tailstock 11 . Workpiece headstock 08 includes a workpiece motor 12 for rotationally driving workpiece 09. Workpiece headstock 08 defines a first axis of rotation about which workpiece 09 rotates.

The swivel table 07 can be tilted relative to the machine bed 03. For this purpose, the swivel table 07 is connected to the machine bed 03 via a swivel bearing 13 on the one hand and to the machine bed 03 via an adjustment element 14 on the other hand.

A dressing unit 16 for dressing the grinding wheel 06 is also arranged on the machine bed 03 and is located axially next to the tailstock 11 in relation to the first axis of rotation. The dressing unit 16 is thus located between the tailstock 11 and the tower 02. The dressing unit 16 is mounted on the machine bed 03 so that it can be displaced in a horizontal direction transversely to the first axis of rotation.

The grinding wheel motor drives the grinding wheel 06 so that it rotates about a second axis of rotation. Tower 02, the first axis of rotation and the second axis of rotation all lie in a vertical plane.

Tower 02 is carried by main stand 01 via a longitudinal guide 17 . The longitudinal guide 17 allows the tower 02 to be displaced axially in the direction of the second axis of rotation, i. H. in the vertical plane comprising the first axis of rotation and the second axis of rotation. By moving the tower 02 with the help of the longitudinal guide 17, the grinding wheel 06 is also moved in this direction.

A vertical guide 18 (shown in Fig 2 ) arranged, which carries the grinding unit 04. The vertical guide 18 allows a vertical displacement of the grinding unit 04 relative to the tower 02. The vertical guide 18 thus allows a vertical displacement of the Grinding wheel 06, so that the grinding wheel 06 can be guided in the vertical direction to the workpiece 09. The vertical guide 18 has a central axis which lies in the vertical plane comprising the first axis of rotation and the second axis of rotation.

2 shows a perspective view of FIG 1 cylindrical grinding machine shown. In this view, the vertical guide 18 located in the tower 02 can be seen, among other things.

3 shows a detailed view of the in 1 cylindrical grinding machine shown. The swivel table 07 is aligned horizontally.

4 shows a further detailed view of the in 1 cylindrical grinding machine shown. In this illustration, the swiveling table 07 is inclined by -10° in relation to the machine bed 03 and thus also by -10° in relation to the horizontal. To set the inclination, the adjustment element 14 is adjusted. The workpiece 09 to be ground is shown in this view. The grinding wheel 06 rotating about the second axis of rotation grinds the workpiece 09 rotating about the first axis of rotation.

5 shows a further detailed view of the in 1 cylindrical grinding machine shown. In this illustration, the swiveling table 07 is inclined by +6° relative to the machine bed 03 and thus also by +6° relative to the horizontal. To set the inclination, the adjustment element 14 is adjusted.

6 shows a side view of in 1 shown cylindrical grinding machine during a dressing process. For dressing, the grinding wheel 06 was adjusted using the longitudinal guide 17 and the vertical guide 18 (shown in 2 ) to the dressing unit 16. The grinding wheel 06 rotating about the second axis of rotation is dressed by the dressing unit 16 .

7 shows a detailed view of the in 1 shown cylindrical grinding machine during a dressing process. For dressing, the grinding wheel 06 was adjusted using the longitudinal guide 17 (shown in 6 ) and using the vertical guide 18 (shown in 2 ) to the dressing unit 16. In addition, the swivel table 07 was inclined by -10° relative to the machine bed 03 and thus also by -10° relative to the horizontal. The workpiece 09 to be ground is also shown in this view.

Reference List

01

main stand

02

Tower

03

machine bed

04

Grinding unit / grinding headstock

05

-

06

grinding wheel

07

swivel table

08

workhead

09

workpiece

10

-

11

tailstock

12

workpiece motor

13

swivel bearing

14

adjustment element

15

-

16

dressing unit

17

longitudinal guide

18

vertical guidance

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 3136396 A1 [0002]
• EP 3351344 A1 [0004]

Claims (10)

Cylindrical grinding machine for grinding a workpiece (09); full: - a machine bed (03) which carries a swivel table (07) on which a work headstock (08) for the rotary drive of the work piece (09) is arranged in a fixed mountable manner and on which a tailstock (11) is arranged in a fixable manner so that the work headstock (08) and the tailstock (11) a first axis of rotation is defined, about which the workpiece (09) can be rotated, the swivel table (07) being pivotable relative to the machine bed (03) about a swivel axis aligned in a horizontal direction transverse to the first axis of rotation is; - a grinding wheel (06) rotatable about a second axis of rotation for grinding the workpiece (09), the first axis of rotation and the second axis of rotation being arranged together in a vertical plane, the second axis of rotation being arranged above the first axis of rotation; - a longitudinal guide (17) for displacing the grinding wheel (06) axially in the direction of the second axis of rotation, the longitudinal guide (17) being arranged in the vertical plane comprising the first axis of rotation and the second axis of rotation; and - a dressing unit (16) for dressing the grinding wheel (06), the dressing unit (16) being arranged in the axial direction next to the tailstock (11) on the machine bed (03) in relation to the first axis of rotation. cylindrical grinding machine claim 1 , characterized in that it further comprises a grinding wheel motor having a motor shaft on which the grinding wheel (06) is mounted, the longitudinal guide (17) carrying the grinding wheel motor together with the grinding wheel (06). cylindrical grinding machine claim 1 or 2 , characterized in that it further comprises a vertical guide (18) for vertical guidance of the grinding wheel (06), with which the grinding wheel (06) to the workpiece (09) can be guided. cylindrical grinding machine claim 3 , characterized in that it further comprises a tower (02) which is carried by the longitudinal guide (17) and which supports the vertical guide (18), the tower (02) in the vertical plane comprising the first axis of rotation and the second axis of rotation is arranged. Cylindrical grinding machine according to one of Claims 1 until 4 , characterized in that the workpiece headstock (08) comprises a workpiece motor (12) for the rotational drive of the workpiece (09), the workpiece motor (12) being fixedly mountable on the pivoting table (07). Cylindrical grinding machine according to one of Claims 1 until 5 , characterized in that the dressing unit (16) comprises a plurality of dressing tools which are arranged next to one another in a horizontal plane, the dressing tools being mounted so as to be displaceable in a horizontal direction transversely to the first axis of rotation. cylindrical grinding machine claim 6 , characterized in that the dressing unit (16) comprises at least one static dressing tool and at least one dynamic dressing tool. Cylindrical grinding machine according to one of Claims 1 until 7 , characterized in that the pivoting table (07) is mounted pivotably on a first axial end of the pivoting table (07) relative to the first axis of rotation in a pivot bearing (13) relative to the machine bed (03), with a vertical distance between a reference to the first Rotation axis related axial second end of the swivel table (07) and the machine bed (03) is defined by an adjusting element (14). cylindrical grinding machine claim 8 , characterized in that the machine bed (03) comprises a base plate on which the dressing unit (16), the pivot bearing (13) and the adjustment element (14) are attached. Cylindrical grinding machine according to one of Claims 1 until 9 , characterized in that the swiveling table (07) can be swiveled by at least ±5° in relation to the machine bed (03).

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