SU413019A1 - - Google Patents

Description

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The invention relates to the field of machine tool construction and relates to the adjustment of flat guides of hydraulic aggregated machine tools operating under mixed friction conditions.

To limit the movement of the moving parts of machine tools with respect to the fixed guides, restrictive strips attached to the moving part with a gap of 0.02-0.03 mm with respect to the fixed guides are widely used.

When cutting forces occur, causing a tilting moment relative to the guides larger than the moment from the weight forces of the machine sub-assemblies, the guiding surfaces of the movable nodes are detached from the fixed guides due to the selection of gaps and deformation of the machine's contacting elements. As a result, increased wear and wedging of the guides, wear of the cutting tool and the guide bushings, deviation from the required accuracy of the workpiece occur on the machines.

The aim of the invention is to automatically maintain a constant position of the guide surfaces of the fixed and movable machine components.

This is achieved by the fact that the pressing assembly is made in the form of two cylinders installed

on the movable machine unit, whose cavities of the same name are hydraulically connected with each other and with the working cavity of the feed cylinder, and the rods interact with one of the arms of the levers mounted on the movable unit, the other arm of which interacts with a stationary machine unit through spherical bearings.

FIG. 1 shows the clamping unit mounted on the power table of a hydroficated aggregate machine; in fig. 2 - power table hydraulic circuit; in fig. 3 shows a force distribution scheme.

The pressing unit consists of two cylinders 1 mounted on the movable node 2 and hydraulically connected to the supply cylinder 3 by means of pipelines 4 and 5. The cylinder 1 rods act on one of the ends of the levers 6 that rotate about an axis fixed to the movable node. At the other end of the arms 6, spherical bearings 7 are installed, the outer rings of which are in contact with the lower directions by the surfaces of the fixed assembly 8.

During the working feed, the oil enters simultaneously in rodless cavities of cylinder 3 and cylinder 1. In case of an increase in axial cutting force Y, pressure in cylinder 3 of supply increases and accordingly in cylinders 1 (force 2 Pi), which

through the levers 6 and the bearings 7, select the gaps in the guides of the slide and the moving table and thereby press the moving parts of the machine towards the fixed ones.

The condition for the absence of detachment of the moving guide surfaces from the stationary ones and the advance of the separation of the guide surfaces is the automatic fulfillment of the inequality condition:

Gh,

where G is the weight of the moving parts of the machine 2;

hi is the distance from the vector G at the center of the sheet metal of the moving nodes to the point a, relative to which separation of the guiding surfaces occurs;

Ghi is the constant moment for a given machine based on the weight of the moving nodes; 2Pi - estimated force on the stock

cylinders 1; hz is the distance from the 2P vector

to point a;

2Pi / i2 is the design moment created by two hydraulic cylinders 1 that prevent the guides from pulling off;

Ghi- -2Pih2-total moment, preventing the separation of the mobile node from the fixed; Pp is the axial cutting force;

I is the distance from the axial cutting force vector to the point and;

RDA - overturning moment from axial cutting force.

In the left part of the inequality moment G / II for

This flock will always be constant, and

the 2Pi / i2 moment will automatically change in proportion to the moment variation from the axial

cutting forces RRYA.

The magnitude of the torque 2Pi / i2 for different aggregate machines can be adjusted by changing the diameter of the cylinder 1 and its installation location hz.

A device for adjusting the selection of gaps in guide metal cutting machines with a hydraulic feed drive and with a pressing unit of the moving units of the machine to fixed, characterized in that, in order to automatically maintain a constant position of the guide surfaces of the fixed and moving parts of the machine, the clamping unit is designed as two cylinders mounted on a movable node of the machine, whose cavities of the same name are hydraulically

interconnected with each other and with the working cavity of the feed cylinder, and the rods interact with one of the arms of the levers mounted on the movable unit, the other arm of which, through spherical bearings, interacts with

stationary knot of the machine.

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