CZ2014254A3 - Device to eliminate forces and moments acting on machine tool frame - Google Patents

Abstract

The machine tool stand (1) is hollow and is positioned on the carriage (6) provided with the hydrostatic carriage surfaces (9) of the carriage (6) over the bed (10). The stand (1) is provided with guide surfaces (13) for the headstock (5) and is provided with a leveling device (3) which is connected to the quill (4) and / or the headstock (5). A hollow inner liner (2) of the rack (1) is located inside the rack (1). The alignment device (3) is located inside the inner liner (2) of the rack (1) and is attached to it at the top. The leveling device (3) and the inner liner (2) are positioned so that they do not touch the stand (1). It is preferred that the stand (1) is mounted on the top plate (7) of the slide (6), while the inner shell (2) of the stand (1) passes through the hole in the top plate (7) of the slide (6) and is attached to the bottom plate ( 8) slide (6). The hydrostatic guide surface (9) of the slide (6) along the bed (10) fixed to the base (12) of the machine tool is then part of the bottom slide plate (8) (6).

Description

The present invention is in the field of machine tool parts or accessories, in particular between frames, beds and stands.

BACKGROUND OF THE INVENTION

Large machine tools, such as horizontal boring and milling machines (called horizontals) are made up of a vertical column, respectively. a stand, on which the headstock moves vertically along the guide surfaces. The headstock has a quill which is horizontally movable towards the workpiece to be processed. The spindle is rotatably mounted in the spindle with the actual tool (boring knife, drill, reamer, cutter, etc.). The stand is usually placed on a sled and bed, which allows its movement in the horizontal direction along the workpiece up to tens of meters.

The general problem of such machine tools is the undesirable influence of gravitational forces and tilting moments on the individual machine parts. When the quill is moved horizontally out of the headstock, all affected machine parts and functional gaps between them are deformed. This results in the spindle end hanging in the order of hundredths to tenths of a millimeter, in extreme cases up to millimeters. Such inaccuracy is essential and very undesirable in precision machining. The magnitude of the tipping moment is given by the product of the extension length and the weight of the quill. The problem of the deformation that is produced is that its magnitude varies according to said key with the length of the protrusion, and therefore the compensating effect, if performed, must vary according to the same key.

There are a number of compensating devices that compensate for the extension of the withdrawable part of the machine tool. One is known, for example, from CZ 302 ^ 259. The essence of this device is that the quill is supported by a pair of support rollers mounted in the headstock. The rollers are connected to the weight by means of a front linkage and a rear linkage guided over the pulleys. The headstock body is also connected to this weight via a separate hinge, guided over a pulley. The front and / or rear and separate hinges are provided with tensioning devices.

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Thanks to this design, automatic leveling of the quill position is achieved depending on the heeling moment. However, a drawback of this and similar devices is the fact that the hinge rollers are mounted in the upper part of the stand. This results in deformation of the stand due to the weight of the weight and the headstock with the quill. Deformation, resp. deflection, the rack typically reaches a size of about 0.05 mm / 1 meter length of the rack. At length, respectively. height, stand 8 to 10 meters, then such a deflection is noticeable and negatively affects the accuracy of machining. The problem with this deformation is that it is uneven, since the rate of deformation increases, as the height increases, non-linearly. As a result, the quill, set in a horizontal position by the device described above, moves with the headstock along the general curve of the deformed stand guide. All reaction variables induced by the movement of the quill in the horizontal direction are also transferred to the rack via pulleys. This results in the entire rack being tilted and other inaccuracies.

The described disadvantages are completely eliminated by the present invention.

SUMMARY OF THE INVENTION

SUMMARY OF THE INVENTION The present invention is based on the construction of a device for eliminating the forces and moments which act on a machine tool stand during machining. The stand is hollow and is placed on a sled. The slide is provided with surfaces of the hydrostatic slide guide on a bed attached to the machine tool base. The stand is provided with guide surfaces for the headstock. In the rack there is a balancing device which is connected to the quill and / or headstock. Inside the stand there is a hollow inner insert of the stand. The alignment device is fixed to the inner liner. The alignment device and the inner liner are positioned so that they do not touch the stand.

This construction is generally designed such that the balancing device is formed by a weight and a set of pulleys through which the weight is connected to the quill and / or headstock. The rollers are then attached to the top of the inner stand insert and the weight is positioned and guided inside the inner stand insert. Thus, neither the pulley nor the weights nor the inner liner of the stand are in contact with the stand, an air gap is maintained between them. As a result, no deformation forces or variable responses are transmitted to the rack from the equalizer. Alternatively, the weight can be replaced, for example, by a set of hydraulic cylinders. The hydraulic pistons can then be attached either to the inner stand insert or to the slide. Another type of alignment device may be a set of ball screws.

In order to ensure the maximum possible filtering of undesirable forces from the stand, it is particularly advantageous if the slide body consists of two horizontal plates. The stand is then fixed to the upper slide plate while the inner liner of the stand passes through an opening in the upper slide plate and is attached to the lower slide plate. The surfaces of the hydrostatic slide guide on the bed mounted on the machine tool base are part of the bottom plate. As a result, reaction forces from the inner stand insert are transferred directly to the bed and machine tool base, thereby avoiding noticeable deformations and oscillations of the stand. The described slide design provides considerably less distortion of the upper part of the slide to which the stand is attached than would be the case with conventional slides.

To prevent unwanted vibration and load on the stand, it is recommended that the stand equipment is attached to the inner liner. Rack equipment means especially the operator platform, tool change station, maintenance platform and the like. The apparatus may be attached to the inner stand of the stand from above or sideways through openings in the stand according to specific requirements.

Thanks to the described construction, no undesirable forces are transmitted to the stand, which would cause its deformation and thus inaccuracy of machining. In combination with conventional balancing systems that compensate for the extension of the withdrawable part of the machine tool, completely negligible deformations and deviations of several thousandths of a millimeter / lm of the stand length are achieved and thus great machining accuracy.

Clarification of drawings

An exemplary embodiment of the proposed solution is described with reference to the drawings, in which Fig. 1 is a side view of the machine showing the forces acting upon the extension of the quill:

Gv - headstock weight,

Gz - weight of the weight,

Gp - weight of quill

Mp - Tilting moment of the quill

Rz - reaction from weight guidance,

Mz - moment acting on the weight due to variable forces in the weight hinges;

FIG. 2 is a front view of the machine;

Fig. 3 is a side view of a stand with a sleeve bearing.

dika, bold

Example of the invention

An exemplary embodiment of the device is designed such that the stand 1 is hollow and is located on the carriage 6. The carriage 6 is provided with surfaces 9 of the hydrostatic slide guide 6 over the bed 10, which is attached to the machine tool base 12. The stand 1 is provided with guide surfaces 13 for the headstock 5. Inside the stand 1 is a hollow inner insert 2 of the stand 1. The alignment device 3 is attached to the inner insert 2 of the stand 1. The alignment device 3 is formed by a weight and a set of pulleys. Through the pulleys, the weight is connected to the quill 4 and / or the headstock 5. The pulleys are attached to the top of the inner liner 2 of the stand 1 and the weight is positioned and guided inside the inner liner 2 of the stand 1. Do not touch the stand

In this example, the stand 1 is mounted on the upper plate 7 of the slide 6. The inner liner 2 of the slide 1 passes through an opening in the upper plate 7 of the slide 6 and is attached to the lower plate 8 of the slide 6. 12 of the machine tool, is part of the lower plate 8 of the slide 6. The stand assembly 11 is attached to the inner insert 2 of the stand 1. An exemplary embodiment of the invention is apparent from Figs. 1 to 3.

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List of reference marks

1- stand

- Inner stand insert

- leveling devices

- quill

- headstock

- sledge

- the top of the sled

- bottom plate of sledge

- hydrostatic slide slide surface

- bed

- attached rack equipment

- machine tool base

- the guide surfaces of the stand

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Claims (3)

Patent Claims! »} This A device for eliminating forces and moments acting on a machine tool stand, wherein the W stand (1) is hollow and located on a sled (6) provided with surfaces (9) of a hydrostatic slide guide (6) on a bed (10) mounted on a base (12) machine tool, wherein the stand (1) is provided with guide surfaces (13) for the headstock (5) and there is located a compensating device (3) which is connected to the quill (4) and / or the headstock (5), characterized by that a hollow inner liner (2) of the stand (1) is disposed within the rack (1), the alignment device (3) being attached to the inner liner (2) of the stand (1) and the alignment device (3) and the inner liner (2) they are positioned so that they do not touch the stand (1). A machine and machine tool eliminator according to claim 1, characterized in that the stand (1) is mounted on the upper plate (7) of the slide (6) and the inner insert (2) of the stand (1) passes through the opening. in the upper slide plate (7) and is attached to the lower slide plate (8) of the slide (6), the surface (9) of the hydrostatic slide slide (6) over the bed (10) mounted on the machine tool base (12), it is part of the bottom plate (8) of the carriage (6). Device for eliminating the forces and moments acting on a machine tool stand according to claim 1 or 2, characterized in that the equipment (11) of the stand (1) is attached to the inner insert (2).