RU2245777C1 - Parametrically vibrated tab disk - Google Patents

Abstract

FIELD: mechanical engineering.

SUBSTANCE: tab disk is assembled with tabs of abrasive paper and mounted at an acute angle to the plane perpendicular to the axis of rotation. The tabs are made of double-sided abrasive paper and are elliptical. The smaller axis of the ellipse is equal to the diameter of the disk. The greater axis is determined depending on the angle of inclination of the disk.

EFFECT: expanded functional capabilities and efficiency.

2 cl, 6 dwg

Description

The invention relates to mechanical engineering, to the machining of metals and can be used for grinding and polishing the surfaces of parts with their dimensionless final machining with flap wheels.

Known prefabricated abrasive tool made in the form of a pair of abrasive wheels fixed at an angle to each other on a common shaft with an axial clearance [1].

The disadvantages of the known tool are the limited technological capabilities for decorative finishing and finishing of shaped surfaces, as well as difficulties in achieving a wide range of quality of the machined surfaces, while having minimal axial rigidity and working only on one side of the peripheral abrasive surface, it is impossible to achieve high performance.

Known prefabricated abrasive tool made in the form of a pair of abrasive wheels fixed at an angle to each other on a common shaft with axial clearance, and the tool is equipped with a tension spring located between adjacent ends of the abrasive wheels, which are installed with the possibility of angular rotation [2].

The disadvantages of the known tool are:

- minimum axial stiffness;

- work only on one side of the peripheral abrasive surface;

- limited technological capabilities for decorative finishing and finishing of shaped surfaces;

- difficulties in achieving a wide range of quality of the treated surfaces.

All this reduces the processing performance and leads to increased tool consumption.

The objective of the invention is to expand the technological capabilities of the tool by providing the possibility of processing with two ends of the petals of which the tool consists, installed at an angle to the axis of rotation, increasing axial stiffness through the use of abrasive petals in the shape of a circle.

The problem is solved using the proposed petal abrasive wheel, which is assembled from the petals of the grinding skin and set at an acute angle to the plane perpendicular to the axis of rotation, and the petals are made of double-sided grinding skin in the form of an ellipse, the small axis of which is equal to the diameter of the circle, and the major axis depends from the angle of inclination of the circle and is determined by the formula

b = D / cosα,

where b is the major axis of the ellipse;

D is the outer diameter of the circle;

α is the angle of inclination of the circle to a plane perpendicular to the axis of rotation.

The circle is equipped with oblique washers installed in pairs from each end, and the angle between the ends of the oblique washer is half the angle of the circle.

In addition, the circle during the preliminary polishing is set at a zero angle.

Figure 1 shows a circle tuned for final polishing, general view; figure 2 is a circle configured for pre-polishing, a partial axial section; figure 3 is a view along a in figure 2; figure 4 - element B in figure 1; figure 5 - element B after half a turn of the circle relative to figure 4; figure 6 is an ellipsoidal petal of a double-sided grinding skin.

The proposed flap abrasive wheel 1 consists of the petals 1 ^{1 of the} grinding skin and is installed at an acute angle α to a plane perpendicular to the axis of rotation. Circle 1 is mounted on spindle 2 and secured with washers 3 with nut 4.

The petals 1 ¹ are cut from a double-sided sandpaper in the shape of an ellipse, the small axis of which is equal to the diameter D of circle 1 in an inclined position, and the large axis depends on the angle α of inclination of circle 1 and is determined by the formula

b = D / cosα,

where b is the major axis of the ellipse;

D is the outer diameter of the circle;

α is the angle of inclination of the circle to a plane perpendicular to the axis of rotation.

For installation and smooth adjustment of the angle of inclination, the circle 1 is equipped with oblique washers 3, which are installed in pairs from each end of the circle.

The angle between the ends of the oblique washer 3 is half less than the angle α of the installation of circle 1.

When the nut 4 is released, by turning one washer 3 relative to the other in each pair of washers, the angle of inclination of circle 1 is set in the range from 0 ° to α _max , where α _max is the maximum possible angle of inclination of the circle to a plane perpendicular to the axis of rotation, which is determined experimentally . Recommended angle α to choose according to the formula

α≤arctg (B / D),

where B is the height of the circle.

When pre-polishing the circle is set at a zero angle (see figure 2). In this case, the peripheral working surface of the circle acquires a wavy shape and, accordingly, a profile in the form of a circular wavy line. The height Δ (Fig. 3) of the wave-shaped protrusion relative to the depression corresponds to the greatest interference during the work of the circle, and the length of the protrusion (equal to half the length of the outer working surface of the circle) corresponds to the largest length of the contact zone of the circle with the workpiece surface being machined. Due to the wavy shape of the working surface of the circle, the main force on the surface to be treated is carried out by the parts of the petals located on the wave-like protrusions and having the greatest deflection (see Fig. 4 or 5).

In connection with the foregoing, in the process of preliminary polishing it is possible to remove large allowances (for example, up to 0.3 mm) when using coarse-grained abrasive skins (grain size 16-80) and high cutting speeds (15-35 m / s). This process is actually a type of grinding and is effective for preparing surfaces for fine polishing and before metal coating.

Finishing polishing with the proposed petal wheel with parametric oscillation (Fig. 1) is intended to reduce the surface roughness parameter (to Ra = 0.1 ... 0.8 μm) without eliminating the deviations in the shape of the parts. The greatest effect of the use of oscillating polishing is achieved during decorative finishing and finishing of shaped surfaces, for example, polishing cylindrical and conical surfaces, processing of molds, dies, etc., polishing curved surfaces of automobile bodies, refrigerators, and others for painting.

Polishing with the proposed wheel is carried out mainly according to one cutting pattern, which is based on the use of high cutting speeds (10 ... 40 m / s), approaching the grinding speed. The peripheral speed of a circle during oscillating polishing of parts made of steel, nickel and chromium is 20 ... 35 m / s; copper, brass and bronze - 16 ... 25 m / s; aluminum, zinc and lead - 12 ... 20 m / s.

The petals made of electrocorundum and silicon carbide skins on a fabric and paper basis with a grain size of 8-M40 and diamond and elbor skins with a grain size of 12-M3 on an elastic bond are most applicable to the circle, the latter being very durable.

For these circles of waterproof diamond-abrasive skins, when processing parts made of steel, cast iron and brass, an emulsion is used as a coolant; from non-waterproof skins - mineral oils.

The proposed petal circles with parametric oscillation expand the technological capabilities of the tool by providing the possibility of processing with two ends of the petals that make up the circles, increase productivity and quality of processing by setting the circle at an angle to the axis of rotation and increase axial stiffness by using abrasive petals in the form of an ellipse.

Sources of information taken into account:

1. A.S. 689823 USSR, MKI B 24 D 5/00. Prefabricated abrasive tool. 1977.

2. A.S. 1692824 USSR, MKI B 24 D 13/00. Prefabricated abrasive tool. A.V. Chemersky and V.N. Cheshev. No. 4700372/08, declared 04/18/89. publ. 11/23/91. Bull. No. 43 is a prototype.

Claims (3)

1. Petal abrasive wheel, assembled from the petals of the grinding skin and installed at an acute angle to a plane perpendicular to the axis of rotation, characterized in that the petals are made of double-sided grinding skin in the shape of an ellipse, the small axis of which is equal to the diameter of the circle, and the major axis depends on the angle the inclination of the circle and is determined by the formula: b = D / cosα, where b is the major axis of the ellipse; D is the outer diameter of the circle; α is the angle of inclination of the circle to a plane perpendicular to the axis of rotation. 2. The circle according to claim 1, characterized in that it is equipped with oblique washers installed in pairs from each end, while the angle between the ends of the oblique washer is half the angle of the circle. 3. The circle according to claim 1 or 2, characterized in that it is installed at a zero angle in the process of pre-polishing.

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