RU2203796C1 - Apparatus for abrasive working - Google Patents

Abstract

FIELD: machine engineering, possibly finish abrasive working of parts at controlling heat flux. SUBSTANCE: apparatus includes body with spindle supporting two flanges engaging with tool. One flange is mounted stationary, other flange is mounted with possibility of motion in axial direction by means of mechanism for axial motion. Grinding disc is mounted on peripheral surface of flanges; disc has portions of annular elastic flexible body with abrasive layer secured to it. Ends of said portions are rigidly secured to different flanges. EFFECT: improved design, enhanced working efficiency, namely improved quality and roughness degree due to intensified working modes provided by oscillations of cutting zone, by rapid change-over of intermittent disc to continuous one and vice versa, increased rigidity of design. 4 dwg

Description

 The invention relates to mechanical engineering and can be used in the final processing of parts with heat flow control.

 A device for abrasive machining with an elastic tool is known, comprising a body with a spindle, inside of which a rod with a tool is placed with the possibility of axial movement [1].

 The disadvantage of this device is the limited technological capabilities, low productivity and quality.

 A device for abrasive machining with an elastic tool is also known, comprising a body with a spindle, on which two flanges facing each other are connected in contact with the tool, one of which is fixedly mounted, and the second is mounted with the possibility of movement in the axial direction, as well as an axial mechanism moving the movable flange, while the said ends of the flanges are made wavy, and the protrusions of one flange are located against the depressions of the other flange [2].

 However, this device has limited technological capabilities, does not allow you to adjust the heat flow directed to the part, low productivity and quality.

 The objective of the invention is the expansion of the technological capabilities of the device through the use of parts of a flexible annular elastic grinding wheel, as well as the regulation of heat flow directed to the part through the use of intermittent grinding, while increasing productivity and processing quality.

 The problem is solved using the proposed device for abrasive machining, comprising a housing with a spindle, on which two flanges are in contact with the tool, one of which is fixed motionless, and the second is mounted with the possibility of axial movement, as well as an axial movement mechanism of the movable flange wherein, on the peripheral surface of the flanges, a grinding wheel is fixed, consisting of parts of an annular elastic flexible body with an abrasive layer fixed to it, so m a manner that the ends of parts are rigidly fixed on different flanges.

 In FIG. 1 shows the design of the proposed device; figure 2 is a view along a in figure 1; figure 3 - the working position of the tool with the most diluted flanges; figure 4 - position of the tool with closed flanges.

 The device comprises a spindle 1, which is mounted with the possibility of rotation in the housing 4 using bearings 2 and 3. To rotate the spindle, a pulley 5 is used, connected by an endless belt 6 to the pulley 7 of the drive motor 8, mounted, for example, on the housing 4.

 On the spindle 1 between the flange 9, which is fixedly mounted with the help of a key and nuts 10, and the axial movement mechanism 11, a movable flange 12 is installed, which has the ability to move along the hub of the fixed flange 9.

 On the spindle 1 between the fixed flange 9 and the housing 4 there is installed an axial displacement mechanism 11 with a movable element - a piston 13, to which the movable flange 12 is attached. In the bore of the piston 13 on the spindle 1 between the fixed flange 9 and the piston 13 a compression spring 14 is installed.

 The axial displacement mechanism 11 can be made in the form of a power cylinder connected to a sleeve 15 mounted on the non-working end of the spindle 1. In this case, the sleeve 15 is connected to a pressure source of the working medium, for example, a hydraulic power station or a pneumatic network.

 On the peripheral surface of the flanges 9 and 12, a grinding wheel 16 is fixed, consisting of parts of an annular elastic flexible body 17 with an abrasive layer 18 fixed to it, so that the ends of the parts are rigidly fixed to different flanges 9 and 12.

 On the periphery of the flanges 9 and 12, parts equal to half-turns of the grinding wheel 16 (as shown in FIGS. 2-4) made in the form of an annular body 17 with an abrasive layer 18 fixed to it can be fixed. In general, the housing 17 of the grinding wheel 16 represents from itself a coil spring, the coil section of which can have a diverse profile. An abrasive layer 18 is applied to the housing 17, for example, a wire-abrasive tool [3] can be fixed on a metal bond or on the housing. Moreover, the abrasive layer 18 is applied to the annular body 17 in such a way that the grinding wheel works both by the periphery and by the ends.

 The ends of the parts or half-turns of the annular grinding wheel 16 are fixed on different flanges 9 and 12 with the formation of a multi-helical helical cutting surface. Fastening is carried out using screws 19 and pins 20, pressed into flanges 9 and 12 to fit H7 / s7.

 The peripheral helical cutting surface thus formed is an intermittent surface with the advantages of intermittent abrasive machining with a continuous grinding process.

 When the device is operating from the engine 8, the spindle 1 rotates together with the flanges 9 and 12, the piston 13 and the tool 16, which processes the necessary surfaces of the part with a peripheral working cutting surface during circular or flat grinding.

 The grinding method of the proposed device is as follows.

 With preliminary roughing, the purpose of which is to remove the maximum allowance, high productivity can be achieved by increasing the cutting conditions, but with traditional grinding this path is fraught with the consequences of marriage due to overheating of the surface layer and the formation of burns and microcracks.

 The use of this device allows for diluted flanges 9 and 12 due to the spring 14 to turn the grinding wheel 16 into an intermittent one having protrusions in the form of screw cutting surfaces and depressions in the form of gaps between the parts of the grinding wheel (Fig. 3).

 When moving to finishing and nursing, the intermittent tool is turned into a grinding wheel with a continuous cutting peripheral surface by converging the flanges 9 and 12 by actuating the axial displacement mechanism 11 (Fig. 4).

 Compared with the usual circle working according to the profile cutting scheme, the proposed tool with diluted flanges has a multi-start screw peripheral cutting surface and additionally removes the allowance from the side edges in the form of narrow layers normal to the work surface. This cutting scheme is called sequential or generator [4].

 The generator circuit is designed to process blanks after forging or stamping, having a crust on the surface.

 In the proposed device, the tool provides a greater thickness and a smaller width of the cut, which intensifies the process, increases processing productivity and tool life.

 A circle with a helical cutting surface has a lower height compared to a traditional one and allows you to save tool consumption.

 The proposed device can also be successfully used for abrasive treatment of flat and cylindrical surfaces of parts made of materials predisposed to defect formation in the form of burns and microcracks due to screw running contact of the circle with the part, which makes it possible to regulate and reduce the heat flux directed to the part.

 Thus, due to the design features of the tool, the device for abrasive processing allows you to expand technological capabilities, provides running screw contact, as well as intermittent cutting during continuous processing.

 During round or flat grinding, a microrelief is formed on the surface of the workpiece in the form of a sinusoidal grid of cutting traces.

 The amplitude of the helix of the abrasive grain cutting path depends on the step of the abrasive cutting surface and the ratio of the speeds of the wheel and the part. The stock removal is carried out by sinusoidal curves. This creates more favorable conditions for cutting abrasive grains. The choice of the optimal ratios of the rotational speeds of the device and the part allows to reduce the pitch of the roughness of the workpiece in comparison with the pitch of the helical groove by an order of magnitude and accordingly reduce their height.

 The processing width captured by the proposed device with diluted flanges (Fig. 3) is several times larger than the width of the parts of the grinding wheel. This increases the processing efficiency and implements the principle of trace repeatability.

 As is known, in traditional grinding, a small part of abrasive grains located on the periphery takes part in cutting and is really cutting. Most abrasive grains fall into previously cut risk scratches, are recessed deeper than cutting ones and do not take part in processing. The location of the peripheral cutting working layer of the proposed device along a helical line increases the number of effectively working abrasive grains that do not fall into previously cut risk scratches and become cutting, improves the self-sharpening of the wheel and the supply of coolant, while reducing the consumption of abrasive material.

 The proposed device can be used at any metalworking enterprises engaged in grinding of both ordinary materials and hard-grinding, and can improve productivity by optimizing the heat stress of the process by selecting the pitch of the screw peripheral surface.

 The proposed device for attaching grinding wheels with a helical peripheral cutting surface allows you to combine the advantages of intermittent grinding with the usual traditional - a solid wheel.

 Production tests showed that the proposed device has a period of unbridge work of 1.7 ... 2 or more times higher than traditional circles, while the wear resistance is at the same level. The application of the proposed device allows to increase productivity by 2 or more times with a simultaneous improvement in quality (improvement in roughness by 1... 2 classes) due to the increase in processing conditions due to the oscillation of the cutting zone, the rapid transfer of the circle from intermittent to solid and vice versa, and to an increase in structural rigidity. At the same time, the consumption of an abrasive tool is reduced by 25 ... 30 percent.

Sources of information
1. French patent 2306786, CL 24 V 3/14, 1976 - analogue.

 2. A. p. USSR 1038194, class 24 V 19/02. Device for abrasive processing with an elastic tool / V.M. Migunov and others. Application 3412463 / 25-08, decl. 03/26/82, publ. 08/30/83. Bull. 32 is a prototype.

 3. A. p. USSR 1516332, class B 24 D 5/00, 17/00. Device for grinding / P.G. Matyukha et al. Application 4385721 / 31-08, claimed. 02/29/88, publ. 10/23/89. Bull. 39.

 4. Rodin P.R. Metal-cutting tools: Textbook for high schools. - 3rd ed. reslave. and add. - K .: Vishka school. Head Publishing House. 1986. S. 218 and 219.

Claims (1)

 A device for abrasive treatment, comprising a housing with a spindle, on which two flanges in contact with the tools are mounted, one of which is fixedly mounted, and the second is mounted with the possibility of axial movement by means of an axial movement mechanism, characterized in that the tool is in the form of an grinding wheel fixed on the peripheral surface of the flanges and made in the form of parts of an annular elastic flexible body with an abrasive layer fixed on it, while the ends of the parts are rigidly fixed Lena on different flanges.

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