RU2100177C1 - Combined tool - Google Patents

Abstract

FIELD: mechanical engineering. SUBSTANCE: combined tool is made up as axially alined grinding wheel and fixed workpiece. The closed groove on the workpiece receives deforming members. The device for fastening the grinding wheel consists of segments with semiaxles and inserts with spherical bushing that allows the inclination of the grinding wheel to be varied. In addition, the tool allows adjustment of outer diameter in radial direction, restoring initial diameter, and positioning the working surface of the grinding wheel and deforming members in a common tangent plane. EFFECT: enhanced reliability. 8 dwg

Description

 The invention relates to the manufacture of tools for finishing finishing of the internal surfaces of the openings of machine parts.

Known combined tool for finishing processing, in which on the mandrel placed a grinding wheel, unloading roller and deforming elements. In the process, when the deforming elements are in contact with the surface to be treated, the discharge roller touches the surface processed by the grinding wheel and rotates freely on the mandrel due to friction forces. The next time the deforming element comes out of contact with the surface to be treated, the unloading roller takes on elastic and thereby eliminates the elastic displacements of the grinding wheel. There are no traces of vibrations on the treated surface [1]
The disadvantages of this tool are the high probability of occurrence of burns (therefore, marriage) with this method of deep grinding, the complexity of the design and large overall dimensions.

Closest to the invention is a tool for finishing machining surfaces of revolution by grinding and surface plastic deformation, consisting of a grinding wheel, in which the peripheral cutting surface is discontinuous, and the deformation elements are placed in sectors, the size and angular arrangement of which correspond to the sectors of the depressions of the peripheral surface of the abrasive wheel, interruption of the contact "machined surface grinding wheel" is ensured, which eliminates the formation of a burn on a surface to be treated [2]
The disadvantage of this tool is the inability to restore the original diameter of the grinding wheel when it is worn. The operation of the tool will require restoration and cutting abilities of the grinding wheel, which is achieved by repeated dressing, and this reduces the diameter of the abrasive wheel and leads to loss of operability of the combined tool as a whole. The only solution to bring the working surfaces of the grinding wheel and deforming elements into one tangent plane is to refuse to edit and completely replace the grinding wheel, which significantly increases the cost of processing and makes the operation of the structure unprofitable.

 The objective of the invention is the repeated restoration of the original diameter of the grinding wheel and the provision of intermittent free grinding without plastic deformation.

 This is achieved by the fact that a combined tool made in the form of a grinding wheel and a body coaxially mounted with it, in a closed creek of which deforming elements are placed next to each other and that the mounting device of the grinding wheel consists of two main and two clamping segments with half shafts between them, making it possible to change the angle of inclination of the grinding wheel and two main and two clamping inserts in contact with a spherical with two flats on the outside and a tapered bore sleeve, fixing position and clamping of the grinding wheel on the mandrel, having its working surface in one tangent plane with deforming elements.

In FIG. 1 shows the design of the proposed combination tool; in Fig.2, view A in Fig.1 with an angle of inclination of the grinding wheel β 0; in FIG. 3 section BB in FIG. 2; in FIG. 4, section BB in FIG. 3; in FIG. 5 is a view of D in FIG. one; in FIG. 6 is a general view of a combined tool with a new grinding wheel rotated by an angle b = β _max and a scan of the trace of the grinding wheel on the machined surface of the hole; in FIG. 7 is a general view of the combined tool after n _max / 2 edits of the grinding wheel rotated through an angle β = β _max / 2 and a scan of the trace of the grinding wheel on the machined surface of the hole; in FIG. 8 is a general view of the combined tool after the (last) dressings of the grinding wheel rotated through an angle β 0 and the development of the trace of the grinding wheel on the machined surface of the hole.

 On the mandrel (spindle) 1 there is a grinding wheel 2 having a metal hub 3. Using two main 4 and two clamping 5 inserts, two main 6 and clamping 7 segments and a spherical with two flats on the outside and a tapered hole inside the sleeve 8, you can change the angle b tilting the grinding wheel relative to the axis of rotation. Moreover, it is possible to change the angle b only in one plane relative to the axle shafts 9 made of easily deformable material, for example, rubber, fixed between the main 6 and pressing 7 segments and entering into the conical holes 10 of the sleeve 8.

 The ends 11 of the grooves of the hub 3 of the grinding wheel 2 and the ends of the flanges 12 of the main inserts 4, the main 6 and the clamping 7 segments are made conical to improve the centering of the above-mentioned grinding wheel mounting structure and its rigidity.

 The main 6 and clamping 7 segments, which are used to accommodate and fasten the axle shafts 9, are interconnected by bolts 14. The angular position of the grinding wheel is fixed by screwing the bolts 15 connecting the main 4 and clamping 5 liners.

 The sleeve 8 with the grinding wheel 2 is placed on the conical surface of the mandrel (spindle) 1 and secured by a nut 16.

 In a stationary rolling mill installed coaxially to the grinding wheel and having a housing 17 in the form of a hollow pipe, a bearing 18 is placed, which serves as a support for the mandrel of the grinding wheel.

 The multi-ball rigid movable rolling mill of this combined tool consists of balls 19 located next to each other in the trough of the disk 20, between the flange 21 of the disk and the thrust bearing 22, the bearing and the disk are fixed to the housing 17 with a cover 23 with bolts 24. In the inoperative zone, the balls are closed casing 25, mounted on the housing 17 with screws 26, in the working area are open.

 To protect against the ingress of coolant and sludge into the mounting device of the grinding wheel, the ends of the latter are covered with safety disks 27.

 The tool works as follows.

 The product is clamped in the chuck of the internal grinding machine, and the combined tool: grinding wheel in the spindle of the grinding head of the machine, rolling mill on the body of the grinding head.

 The grinding wheel 2, in contact with the peripheral axially displaced cutting layer of the grinding wheel, installed at an angle to the axis of rotation, with the workpiece surface, removes the established allowance, and the deforming elements 19, due to the friction force, are rolled between the surfaces of the part and the disk 21 and produce the final rolling of the treated surface .

 The axially displaced cutting layer of the grinding wheel 2 eliminates the formation of burns on the processing surface, and the nearby balls, practically no less than two involved in the work, ensure continuity of plastic deformation of the surface of the product, which eliminates vibrations and vibrations of the abrasive wheel 2 and reduces the roughness of the treated surface.

As the grinding wheel wears, it decreases in diameter and it is necessary to restore its original size. To adjust the size of the outer diameter in the radial direction and restore the original size, rotate the grinding wheel in the plane passing through the axis of rotation by the value of the angle b _t determined by the formula β _t arc cos D / (D + 2t), where D is the outer working diameter of the combined tool, mm; t is the thickness of the abrasive layer to be removed for one straightening, mm, and the maximum angle of inclination is prescribed from the condition of the continuous grinding zone at one revolution of the grinding wheel, determined by the formula β arc sin (H / D), where H is the height of the grinding wheel.

As the grinding wheel wears out and the angle of inclination decreases with each subsequent straightening, the grinding width will decrease from H max to H (Fig. 6
8), but intermittent grinding remains, as can be seen from the above scans of the trace of the grinding wheel on the machined surface of the hole.

The working area S _{p of the} periphery of the grinding wheel involved in cutting from S _{p max} p DH of the new wheel to S _{p min} S _{p max} / 2, which is determined by the formula, will also decrease
S _p = πDH (2-β / 180) + D ² tgβ.

Claims (1)

 A combined tool comprising a grinding wheel with a device for mounting it on a mandrel and a cylindrical body coaxially mounted with it, in a closed stream of which deforming elements are placed next to each other, characterized in that the mounting device of the grinding wheel is made in the form of a sleeve mounted on a mandrel with a conical hole and an outer spherical surface with two flats, two pairs of main and pressure segments with semi-axes located between them and two pairs of main and pressure inserts placed in the case of the circle, with the segments with half shafts mounted on the side of the flats of the sleeve, and the liners with the possibility of contact with the spherical surface of the sleeve, and the grinding wheel is mounted with the possibility of rotation with subsequent fixation in the plane passing through the axis of the circle, from the condition of its working surfaces in one tangent plane with deforming elements.

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