RU2285603C1 - Petal type wheel with local contact - Google Patents

Abstract

FIELD: machine engineering, possibly grinding and polishing surfaces of parts.

SUBSTANCE: petal type wheel includes two flanges and petal pack mounted with use of tapered washers arranged in ends by acute angle relative to plane normal to rotation axis. Said flanges are made with possibility of clamping petal pack at forming radial waves. Petals are made by cementing ends of strips of double-side diamond-abrasive grinding cloth for forming shells that are turned and arranged across rotation axis. Said strips have width less than radius but more than radius half of petal type wheel and length equal to length of its circumference. Petals are mounted with possibility of extending in radial direction according to their wear degree for restoring outer diameter of wheel.

EFFECT: enlarged manufacturing possibilities, lowered consumption of abrasive material.

10 dwg, 1 ex

Description

The invention relates to mechanical engineering for the mechanical processing 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 that make up the tool, installed at an angle to the axis of rotation, increasing axial stiffness due to the use of abrasive petals in the form of a circle with radial waves, as well as the economical use of abrasive material and cheaper manufacturing tool.

The problem is solved using the proposed petal wheel with a local contact, 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, using oblique washers located at the ends, and the petals are made by gluing strips of width less than radius, but more than half the radius of a circle and a length equal to its circumference from a double-sided diamond abrasive grinding skin with the formation of shells that are deployed and are located across and rotation, and two flanges, allowing you to clamp the package of the petals with the formation of radial waves, while as the petals wear, they extend in the radial direction, restoring the outer diameter of the circle.

The design features of the circle is illustrated by drawings.

Figure 1 shows the proposed petal circle with local contact, a partial longitudinal section; figure 2 is a view of figure 1; figure 3 is a strip of double-sided grinding skins, a blank for the manufacture of a petal; figure 4 is a shell made of strip (figure 3), a semi-finished petal; figure 5 is a new, unworn petal with a symmetrical arrangement of radial internal waves relative to the plane of the petal; in Fig.6 is a view of B in Fig.5; figure 7 - element In figure 1; on Fig - element In through a half-turn of the tool relative to Fig.7; figure 9 is the most worn petal; figure 10 is a view of B 'in figure 9.

The proposed flap wheel has a peripheral diamond-abrasive working cutting part 1 with axial displacement due to the installation of the wheel at an angle α to the plane perpendicular to the longitudinal axis on the spindle 2 using oblique washers 3 located at the ends and secured by a nut 4.

The diamond-abrasive wheel 1 is made in the form of a combined petal wheel and consists of petals 5. The petals 5 are made of strips of a double-sided grinding skin (Fig. 3) with a width h less than a radius, but more than half the radius of a circle, i.e. R> h> R / 2 and a length πD equal to its circumference. Shells are glued from strips (Fig. 4), having previously prepared strips for gluing by overlapping by cutting smaller ends with the removal of grinding material from both ends of the tape in the area under the seam. Then one of the ends of the shell is turned inward with the formation of radial waves. Figures 5 and 6 show a new, unworn petal with a symmetrical arrangement of radial internal waves relative to the plane of the petal. Turning the shells inward is easy to do if you use special flanges 6, which allow you to form a package of petals with the formation of bilateral radial waves 7 and which we use in the proposed tool for attaching a package of petals. As the petals wear, they are pulled out in the radial direction, restoring the outer diameter D. This design of the petals allows you to constantly restore the outer diameter of the rapidly wearing flap diamond abrasive tools and make full use of expensive diamond abrasive material (see Figs. 9-10).

When restoring the outer diameter D of the petals 5, it must be borne in mind that d ₅ , the inner diameter of the petals, is not larger than the outer diameter d _{6 of the} clamping flanges 6, otherwise the petals will not be clamped.

Due to the wavy shape of the inner surface of the petals of the diamond-abrasive wheel, its rigidity is higher than that of traditional petal circles, the main force impact on the surface being treated is greater due to deflections of the peripheral parts of the petals (see Figs. 7-8).

In connection with the above, in the polishing process, it is possible to remove large allowances (for example, up to 0.3 mm) when using coarse abrasive skins (grain size 16-80) and high cutting speeds (65-70 m / s). This process is actually a form of grinding and is effective for preparing surfaces for fine polishing and before metal coating.

Finishing polishing with the proposed petal wheel with local contact is intended to reduce the surface roughness parameter (to Ra = 0.1 ... 0.8 μm). The greatest effect of the use of oscillating polishing is achieved with decorative finishing and finishing of shaped surfaces, for example polishing of cylindrical and conical surfaces, processing of molds, dies, etc., polishing curved surfaces of automobile bodies, refrigerators, etc. for painting.

Polishing by the proposed tool is carried out mainly according to one cutting pattern, which is based on the use of high cutting speeds (35 ... 40 m / s), approaching high-speed grinding.

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 tool, while the latter are highly resistant.

For the proposed tool from waterproof diamond-abrasive skins, when processing parts made of steel and cast iron, an emulsion is used as a cooling liquid; from non-waterproof skins - mineral oils.

The proposed technical solution improves the efficiency of using a polishing tool that can restore the outer diameter and allows processing using the entire peripheral working part of the tool while maintaining the advantages of the intermittent grinding process.

Example. On a modernized machine mod. 16K20T1 polished the workpiece in the form of a shaft with a diameter of 20 mm from steel 45 in a normalized state. The upgrade consisted of installing a device with an outer diameter of 250 mm and an individual drive on the transverse caliper.

Petals were made from a waterproof double-sided fabric elbor (sandblasting sand powder LO 50/40, OST 2 MT79-2-88) sanding pellets with a grain size of 50/40, made according to TU 2-036-0224450-014-89 electrostatically in the form of a grinding bin with a width of 60 mm and a length of up to 100 running meters, a bunch - resin SFZh-3039, the base fabric - chiffon. The tape was cut into strips of 60 × 805 mm in size and glued with an overlap into the shells, having previously cut the smaller ends to remove the grinding material from both ends of the tape in a section under the 10 mm wide seam. The petal circle is made up of 15 petals.

An individual electric drive rotates the flap wheel at a peripheral speed of 32.5 m / s (2500 min ^-1 ). The linear speed of rotation of the workpiece is 0.05 m / s (50 min ^-1 ). Coolant was supplied to the treatment zone as a 5% emulsion solution. The angle of inclination of the petal circle was α = 1 ° 12 ^I.

The set roughness Ra is 0.32 μm. The tool allowed to increase the productivity of the process by 2.1 times and reduce the consumption of abrasive by 32%.

The circle extends the technological capabilities of processing thanks to a more rigid design and the installation of diamond-abrasive blades at an angle to the axis of rotation, which allows to increase the cutting conditions, and this increases the productivity of processing by 2 ... 2.5 times, improves the quality and roughness of the processed surface.

The proposed tool allows you to restore the outer diameter and process using the entire peripheral working part of the tool while maintaining the advantages of the intermittent grinding process, it is simple in design and reliable in operation, while the consumption of an abrasive tool is reduced by 30 ... 35%.

Information sources

1 A.S. 689823 SSS, 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 (1)

A petal circle with a local contact, containing a package of petals from a sandpaper, mounted at an acute angle to a plane perpendicular to the axis of rotation, using oblique washers located at the ends, characterized in that it is provided with two flanges made with the possibility of clamping the package of petals to form radial waves, and the petals are made by gluing at the end of the strips, the width of which is less than the radius and more than half the radius of the circle, and the length is equal to the length of its circumference, from a double-sided diamond-abrasive polished hydrochloric skins to form shells that are deployed and arranged transversely to the axis of rotation, the lobes are mounted for extension radially as they wear to restore the outside diameter of a daisy wheel.

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