Training 

Extrusion press: alignment of fixed parts

See. begining: Basic principles and Instruments.

Fig. 1 – The press center line is the line joining the platen centers. All the platen-centered components should lie on this line [1]

A reconciliation of the extrusion press for the production of aluminum profiles begin with its fixed parts. For fixed parts of the press are, first of all, Stanishev Presse, its master cylinder, front and rear cross members.

Initial installation media

The press as a whole must be set horizontally and vertically. During the initial installation of a frame press it usually expose on steel chocks. Lining mounted between the frame and the foundation of the press. Thus a frame is aligned horizontally and then operate the screed thickness from 15 to 40 mm. Anchor bolts are tightened to the place of installation pads. Lining to prevent distortion of the frame put on both sides of the anchor bolt. The accuracy of the horizontal alignment is usually 0,04 mm / m.

Over time, the press frame may lose its horizontal alignment. The reasons may be as follows:

  • subsidence of the foundation or soil under it;
  • destruction of the foundation;
  • screed destruction;
  • loosening of anchor bolts;
  • the impact of climatic conditions;
  • mechanical damage to the press frame.

Before you align a frame extrusion press is necessary to ensure the normal state of the basement and tie, as well as the absence of loosening anchor bolts. Not all that was said above and will be discussed below is directly related to all modern extrusion presses. In each case it is necessary to take into account the design features of a particular press. However, the general principles of alignment remain the same.

Reconciliation of the press frame

When aligning the press, the bed of the extrusion press is aligned in all directions: along, across and along both diagonals. the horizontal deviation should be no more than 0,04 mm 1 meter. The bed is sure to align, if its deviation from the horizontal reaches more than 0,25 mm per meter.

Align the base frame is best for her guide. If the guides do not have the horizontal plane, and they are prismatic, then apply special Adapters (Fig. 2) to obtain horizontal surfaces, friendly alignment. When alignment is scheduled from 12 to 14 points along the length of each rail. One of the guide is selected as a reference plane, and then measure its relative all other points.

Fig. 2 – Adapter Block for Angled Guide Ways [1]

Aligning the main press cylinder

The main cylinder extrusion press is rigidly connected to the rear cross member. Rear cross member must be perpendicular to the guide frame and the center line of the frame, and also parallel to the front crossmember. For, to check it is necessary to establish measuring angle on a plane machined front crossmember and check horizontal level of the machine-building.

The maximum deviation from perpendicularity should be less than 0,04 mm / m.

When using a three-plane laser level (Fig.. 3), the measured angle between the base frame and main guide cylinder, and between this guide and the front cross member. In this way, check their perpendicularity to the guide frame.

Another way to align the master cylinder is to extend the ram so far, so that it can accommodate a machine-building level (about 0,5 m).

In this position, the ram must be fully supported by its carrier sleeve. The slide should be no worse than the alignment 0,04 mm / m. If the rear cross member is perpendicular to the guide surface, and the ram is not in a horizontal plane, it means, that the slide bearing bush, apparently, worn out and needs to be replaced.

The guide shoe master cylinder should be in this position only slightly touch the guide frame.

Fig. 3 – Three-plane laser level (See www.hamarlaser.com) [1]

Reconciliation of clamping columns press

An important step in the reconciliation of the extrusion press is to check the horizontality of his tie columns in both directions - along each column and across the upper and lower pairs of columns on both their ends. Columns need to be aligned in a horizontal plane to within 0,04 mm / m.

Aligning parallel front and rear crossmembers

The distance between two cross members measured in each column, wherein the container must be at the operating temperature. Measurements are made using a device, which is called “Trammel Rod device” (Fig. 4), wherein always machined surfaces. In some cases, it may be easier to measure the distance between the inner nut tightening columns. In this case, the measured thickness of the micrometer nut and add them to the readings of the bar-shtangeltsirkulya.

The maximum difference between the lengths of the columns should be in accordance with the manufacturer's recommendations press. If such recommendations are not available, the maximum allowable difference between the lengths of columns take 0,075 mm. The measurements should be carried out both in the loaded, and unloaded press.

Relatively new media can have on the columns of the protective sleeve, which fit precisely over the length. In this case, there is no need to measure the distance between the cross - abuse squareness judged by a gap between the arms and crossbars.


Fig. 4 – Trammel Rod device [1]

Preloading clamping columns

These controls were carried out according to manufacturer's instructions extrusion press. If no such instructions, the procedure can be as follows. Pre-loading of columns is usually carried out an increase in efforts to press 10 % above the nominal. In this case, use the ram, to stretch the column. Then tighten the inner nut and counter them. So get pre-compression columns.

Internal nuts should be tightened even at full press force, so that even the dipstick 0,025 mm could not get into the gap between the nut and the flange. Similarly, when the load is removed there should be no gap between the crossbar and the outer nut. If the columns fitted sleeves, between the sleeve and the cross-members should not be any gaps. Any such gap indicates the preload loss columns and requires you to reinstall the nuts and check the squareness of cross.

Source:

1. Extrusion Press Maintenance Manual, ed. Al Kennedy –