RU2236933C1 - Device for grinding and honing - Google Patents

Abstract

FIELD: mechanical engineering.

SUBSTANCE: device has two coaxial and axially aligned shafts, grinding disk whose grinding layer is shifted in the direction of the operation feeding, and disk with abrasive honing bars. The bars are pivotally connected with the disk for permitting radial unclamping and rolling in the periphery direction. The hollow shaft is provided with grinding disk. The disk with honing bars is movably mounted on the spherical neck of the central shaft through the faceplate for permitting oscillation. The face of the faceplate engages the face cam mechanism of oscillation which is the faceplate of the grinding disk. The disk is mounted symmetrically with respect to the center of the sphere of the neck on the double slide bearing. The honing bars are interconnected through flexible rings for restricting free and arbitrary rotation of the honing bars into the pivot.

EFFECT: enhanced efficiency and quality of grinding.

1 cl, 2 dwg

Description

The invention relates to mechanical engineering, to metalworking, and in particular to devices for fine combined abrasive-diamond processing, and can be used for grinding and honing hard-working materials, prone to the appearance of burns and microcracks, in particular, on circular grinding machines, CNC machines, flexible production modules for finishing operations.

A device for grinding, which contains two grinding wheels with the same diameters [1]. The latter are placed on coaxial coaxial shafts and inform them of rotation in opposite directions and the feed movement. The workpiece is reported reciprocating relative to the circles. The first circle is mounted rigidly on the hollow shaft at an angle to a plane perpendicular to the axis of rotation. Oscillation is reported to the second circle, for which it is mounted on the spherical neck of the central shaft using the interface plate conjugated with the last one. The end face of the said faceplate is intended for contact with the end face cam mechanism of the oscillation, which is the face plate of the first circle. The outer peripheral surface of the second circle is tucked in a sphere and arranged symmetrically with respect to the center of the neck sphere.

A significant disadvantage of the known device is the ineffective operation of the second spherical wheel due to the small contact area with the surface being machined (theoretically, the point of contact of the spherical abrasive surface of the wheel with the surface being machined is), which reduces productivity and processing quality.

The closest analogue to the proposed device is a device that implements a method of combined quasi-continuous finishing, in which the treatment is carried out by a grinding wheel and a disk with abrasive radially expandable bars [2].

The disadvantages of the known device are: the inability to control the frequency of the longitudinal reciprocating oscillating movement of the bars, which is assigned depending on the cutting properties of the abrasive material, which reduces the tool life and processing productivity, in addition, being in a free state, the abrasive bars occupy an arbitrary position and when in contact a blow occurs with the surface to be treated, which leads to the occurrence of vibrations, to chipping and chipping of the abrasive, and may also damage the work surface. All this reduces the quality and productivity of processing.

The objective of the invention is the ability to control the frequency of the longitudinal reciprocating oscillating movement of the honing bars regardless of the rotational speed of the wheel when establishing optimal cutting conditions, as well as improving productivity and processing quality.

The problem is solved using the proposed device for grinding the bodies of revolution, containing a grinding wheel with axial displacement in the direction of the working feed and a disk with abrasive honing blocks articulated on it with the possibility of radial expansion and rolling in a circular direction along the machined surface, and it is equipped with coaxial coaxial shafts, the central of which is made with a spherical neck, and an end-face cam mechanism of oscillation, while the grinding wheel it is rigidly mounted on the hollow shaft at an angle of axial displacement to a plane perpendicular to the axis of rotation of the device, and the disk with honing bars is movable with the possibility of oscillation and regulation of its frequency regardless of the frequency of rotation of the grinding wheel on the spherical neck of the central shaft by means of a face plate connected to it, the end of which is intended for contact with the end cam oscillation mechanism, which is the faceplate of the grinding wheel, the disk being located symmetrically with respect to the center of the sphere Menus on the double thrust rolling bearing rotatably relative to the neck, and honing stones are linked with each other to the two ends of the flexible ring to limit free rotation and arbitrary in the hinge bars.

In addition, the device is equipped with a set of oblique washers for stepwise regulation of the amplitude of the oscillation of the disk with honing blocks and grinding wheel.

The invention is illustrated by drawings.

Figure 1 shows a device for grinding; figure 2 is a section along a - a in figure 1.

The proposed device for grinding is designed for combined simultaneous roughing (grinding) and finishing (honing) processing of bodies of revolution, in which the workpiece and grinding device communicate rotational movement and feed movement along the surface to be machined. The device is also applicable for the treatment of flat surfaces on modernized surface grinding machines by the periphery of the grinding device.

The grinding honing device consists of a grinding wheel 1 with an axial displacement in the direction of the longitudinal working feed of the cutting layer and the disk 2 having abrasive radially sliding honing blocks 3 as working elements.

The grinding wheel 1 and the disk 2 with honing bars 3 are placed on the coaxial coaxial shafts 4 and 5, and the wheel 1 is mounted rigidly on the hollow shaft 4 at an angle of axial displacement to a plane perpendicular to the axis of rotation, and the disk 2 on the central shaft 5.

In order to inform the disk 2 of oscillating movements in the longitudinal direction, it is movably mounted on the spherical neck 6 of the central shaft 5 with the help of the ball 7 conjugated with the last faceplate, through the balls 8 and the double thrust rolling bearing 9, while the disk 2 is placed symmetrically with respect to the center of the neck sphere 6 .

The large end face of the faceplate 7 is intended for contact with the end cam of the oscillation mechanism 10, which consists of balls and faceplate 11 of the circle 1.

On the disk 2, the honing bars 3 are pivotally mounted with the possibility of radial expansion and are connected to each other from two ends by flexible rings 12, restricting the free and arbitrary rotation of the bars in the hinge. In this case, the abrasive bars occupy a certain position, namely, the working surface of the bars will always be parallel to the surface being machined and when the bars come in contact with it, there is no impact, the processed surface is not damaged; no vibrations occur, no chips and abrasive spalling is not observed. All this improves the quality and productivity of processing.

The hinges of the bars 3 can be carried out by known methods, for example, using a screw 13 with a spherical end face of the head and spring 14.

Stepwise adjustment of the angle of inclination of the circle 1 is carried out using a set of oblique washers 15, the ends of which are made at different angles.

With a change in the angle of inclination of the circle, and therefore the angle of inclination of the end face of the faceplate 11 of the oscillation mechanism, the amplitude A _{x of the} longitudinal vibrational movement of the honing bars changes, which affects the productivity and quality of processing, i.e. the magnitude of the amplitude of the oscillating oscillatory motion is carried out stepwise using oblique washers 15.

The oscillation frequency of the honing bars 3 is controlled by the rotation frequency of the central shaft 5, regardless of the rotation speed of the grinding wheel 1. Since Since the coaxial shafts 4 and 5 have independent drives, it is possible to set their movements both multidirectional and in one direction. This extends the technological capabilities of the device.

The processing features of the proposed device are as follows. Due to the axially displaced cutting layer of the grinding wheel, intermittent grinding is observed for some cross sections of the workpiece, which is accompanied by a low cutting temperature compared to traditional grinding, and even with increased cutting conditions there are no burns and microcracks on the treated surface.

In general, this grinding wheel treatment is a continuous cutting process, which provides oscillation of the thermal field, and the angle of inclination of the wheel allows you to increase the number of abrasive grains involved in cutting.

Following the grinding wheel, the surface to be treated is finished by abrasive honing stones, which have the ability to radially move and are pressed against the surface to be treated with a certain force. The bars are run on the machined surface, making reciprocating axial movements with amplitude A _x , which depends on the diameter and angle of inclination of the tool.

Due to this, scratches are formed on the treated surface with abrasive grains, the direction of which is perpendicular to the previous ones obtained by the grinding wheel.

The use of the proposed device for grinding allows you to process using the entire peripheral working part of the tool while maintaining the advantages of intermittent grinding and honing.

The performance of the proposed device for grinding increases by 2 ... 2.5 times, and the surface roughness by 1 ... 2 classes compared with traditional grinding. In this case, the consumption of abrasive material is reduced by 1/3.

On the internal grinding modernized machine mod. 3K228B using the proposed device was processed through hole with a diameter of 60N7 ( ^+0.03 ) and a length of 60 mm The modernization consisted in the installation of coaxial coaxial spindles, one of which is hollow, inside the latter there was a central spindle on bearings. Each spindle had an individual drive and independent speed control. The machine is equipped with a device for active control of workpieces. The roughness parameter of the treated surface is Ra = 0.63 μm. The allowance on the side of 0.2 mm. The workpiece material is steel 45, hardened, hardness HRC 45. The characteristic of the grinding wheel is 24A25PS25K8A, the diameter of the new wheel is 50 mm. Abrasive whetstones: grain material 63C, grain size M40, hardness CM1, bond - ceramic, number of whetstones - 6, length of whetstones - 30 mm, width - 16 mm. Processing was carried out under the following cutting conditions. The frequency of rotation of the grinding wheel was taken 13000 min ^-1 , the frequency of rotation of the Central spindle with abrasive bars - 320 min ^-1 ; wherein the speed of the longitudinal movement of the bars is 10 m / min, and the oscillation frequency of the bars is equal to the frequency of rotation of the grinding wheel. A longitudinal feed was set at 5390 mm / min. Cross feed - 0.006 mm / dv. stroke (1.5 times more than with conventional grinding). Coolant - emulsion. The angle of inclination of the grinding wheel to a plane perpendicular to the axis of rotation is 10 °. The amplitude in this case was A _x = 8 mm. The radial pressure of the honing bars was 0.05 ... 0.06 MPa. To ensure the required quality and dimensional accuracy of processing, it took 0.6 min of main time, which is two times faster than with traditional grinding.

The use of this device for grinding allows you to exclude the operation of semi-grinding due to the improvement of surface roughness by 1-2 classes, while the consumption of abrasive material is reduced by 1/3.

Sources of information

1. RF patent 2162398, MKI 7 V 24 V 1/00, 7/02, 5/12, 45/00. Grinding method. Stepanov Yu.S., Afanasyev B.I. Application 99108489/02, claimed 04/21/1999, publ. 01/27/2001, bull. No. 3.

2. RF patent 2120368, MKI 6 V 24 V 5/06, 1/00. The method of combined quasi-continuous processing. Stepanov Yu.S., Afanasyev B.I. other application 96116348/02, the application. 08/07/96, publ. 10/20/1998, bull. No. 29 is a prototype.

Claims (2)

1. Device for grinding honing bodies of revolution, comprising a grinding wheel with axial displacement of the cutting layer in the direction of the working feed and a disk with abrasive honing stones pivotally mounted on it with the possibility of radial expansion and rolling in a circular direction along the machined surface, characterized in that it is provided coaxial coaxial shafts, the central of which is made with a spherical neck, and the end cam oscillation mechanism, while the grinding wheel is mounted rigidly on the polo m to the shaft at an angle of axial displacement to a plane perpendicular to the axis of rotation of the device, and the disk with honing bars is movable with the possibility of oscillation and regulation of its frequency on the spherical neck of the central shaft by means of a face plate connected to it, the end of which is intended for contact with the end cam oscillation mechanism, which is the faceplate of the grinding wheel, and the disk is located symmetrically with respect to the center of the neck sphere on a double thrust rolling bearing with the possibility of rotation flaxen the neck, and honing bars are connected to each other from two ends by flexible rings to limit the free and arbitrary rotation of the bars in the hinge. 2. The device according to claim 1, characterized in that it is equipped with a set of oblique washers for stepwise regulation of the amplitude of the oscillations of the disk with honing blocks and grinding wheel.

Images