RU2000916C1 - Method for machining shaped surfaces of revolution - Google Patents

Abstract

Usage: in mechanical engineering during the final abrasive treatment of shaped surfaces of parts such as raceways of the outer and inner rings of the bearing. The essence of the invention for the tool is set to the main working movement in a plane that does not coincide with the plane of symmetry of the profile of the surface being machined, and as a tool take a toroidal grinding wheel whose rotation axis positioned at an angle of 5 to 20 °; to the axis of rotation of the workpiece The tool is moved with a working feed along the line of the shortest distance between these axes 6 silt, 1 taba

Description

The invention relates to mechanical engineering, in particular to abrasive finishing operations on shaped surfaces of parts such as raceways of the outer and inner rings of bearings.

A known method of surface treatment is rotation by a cup grinding wheel, the axis of rotation of which intersects with the axis of rotation of the workpiece. The disadvantage of this slob is its limited technological capabilities, since it allows the processing of surfaces with a relatively simple geometric shape, mainly the spherical surfaces of parts.

A known method of surface treatment with a proform shape part by grinding by copying the part shape of the abrasive wheel profile, the axis of rotation of which is parallel to the rotation axis of the workpiece, and its predetermined shape is provided by editing by copy. This method does not provide high accuracy of the part profile due to the significant error that occurs when dressing the wheel, and high processing efficiency, since the contact line of the tool and the workpiece is limited by the line of their profile.

The closest to the proposed physical essence and the achieved effect is a method of processing the surface of rotation with a toroidal grinding wheel, in which the axes of the part and the wheel are angled to each other, tell them to rotate around its axis, and the working feed of the wheel is carried out in a circular motion . This method has limited technological capabilities, as it is intended for machining the outer rings of bearings.

The aim of the invention is to improve the quality and expand technological capabilities by treating both internal and external shaped surfaces.

This is achieved by the fact that in the method of processing shaped surfaces of revolution, in which the axis of the grinding wheel with the toroidal working surface is set at an angle to the plane-longitudinal section of the part and the circle and the part are informed to rotate around their axes and the circle to work. The feed feed, the axis of the grinding wheel and the workpiece are set in parallel planes from the conditions of the location of the point of intersection of the workpiece axis and the projection of the wheel axis onto the plane of the longitudinal section of the workpiece in the plane of symmetry of the latter, while the work feed is carried out along the shortest distance between the axes

the circle and the part, and the angle between the axis of the circle and the plane of the longitudinal section of the part is chosen 5-20 °.

Since the axes of the grinding wheel and the part are set in parallel planes based on the condition of the location of the intersection point of the part axis and the projection of the axis of the wheel on the plane of the longitudinal section of the part in the plane of symmetry of the latter, the working feed is carried out along the shortest distance between the axis of the wheel and the part, and the angle between the axis of the circle and the plane of the longitudinal section of the part is chosen 5–20 °; as a result of grinding, the workpiece profile takes on a shape that depends on four geometric parameters: the diameter of the grinding wheel angle, torus radius, angle of inclination of the axis of the circle and the workpiece, and the distance between these axes. This makes it possible, by adjusting these parameters, to give the workpiece a profile of any, even very complex form.

Figure 1 shows a diagram of a method of processing the outer ring of a ball bearing; figure 2 - dependence of the shape indicator and the errors of the surface treatment profile on the angle of inclination of the circle; in Fig.3 is a view from the side of the grinding wheel when grinding the inner ring of the ball bearing; Fig. 4 is a view in the plane of the longitudinal section of the workpiece in the direction of arrow A; figure 5 is a view from the side of the grinding wheel when grinding the outer ring of the ball bearing; Fig.6 is a view in the plane of the longitudinal section of the workpiece in the direction of arrow A.

A toroidal grinding wheel 1 (Fig. 1) with a torus radius RT and a profile radius r rotates with a frequency of pcr around an axis 1-1, inclined at an angle a to the axis of the workpiece 2, which is the outer ring of a ball bearing.

From Fig. 3 and Fig. 5 more clearly than from Fig. 1. it can be seen that the axis 1-1 of the circle I and the axis 11-11 of the workpiece 2 are not parallel to each other and do not lie in the same plane: the axis 11-I is in the plane of the longitudinal section of the workpiece (in its axial section), and the axis 1-1 of the circle I is inclined to this plane at an angle a. As a cross section of the workpiece (Figs. 4 and 6), one is considered that passes through the shortest distance between the axes 11-M of the workpiece 2 and 1-1 of the wheel 1, which coincides with the feed direction S of the cutting wheel. a workpiece rotating at a frequency pi.

Point M is an arbitrary point of the line of contact between the circle and the workpiece lying in the X O Y plane. The distance between the axes 1-1 of the circle I and 11-11 of the workpiece 2 is E.

Figure 1 shows that due to the inclination of the circle, the center A of the profile of the circle I in the X O Y plane is shifted relative to the plane of symmetry Z 0 X by the distance B A, and the profile of the surface to be machined takes on a complex shape described by four-parameter equations

Shann HI necyrKON works, the profile of kotro-o is described by the equation

x gsh

- V vT-Cv

(2)

where rh is the radius of the ball in the ball bearing (rh 4.765 mm),

with. p - coefficient and indicator of the shape of the profile of the raceway (with 5

4 8)

 P

sin a

where E, RT, r and a are the constant profile parameters of the treated surface.

/ 3- the angle of inclination of the tangent profile to the axis OY;

J diameter along the bottom of the gutter; U is the profile variable parameter In equation (1), the upper sign should be used to describe the profile of the inner ring of the ball bearing, and the lower sign should be used to describe the profile of the outer ring.

Since the equation for the profile of the part is determined by four parameters, by adjusting the values of these parameters (A, RT. G and a), you can draw a line through seven profile points - one central, the top of the profile, and six symmetrically located points of the side profile lines . This makes it possible to manufacture parts of any complex shape with high accuracy. For example, in this way it is possible to produce ball bearings rings with increased service life. So. the table shows the coordinates of the side of the profile of the inner ring of ball bearing No. 206 (D 36.47 mm), the trough of which is obtained by the proposed method and has a profile described by equation (1) at E - 270 mm; Rr 250 cm, g 2.289 mm: a - 20 °. The coordinates of the points of the side part of the bearing profile are shown in the same figure. As can be seen from the table, the profile lines of the groove of the ball bearing ring with rational geometry (2) and the profile (1) of the profile of the groove of the bearing bearing obtained by the proposed method intersect at four points y - 0; at 0.5; 2 and 3.8. Maxim ine profile error 22 m to m

The resulting profile shape and the profile error caused by the wear of the wheel depend on the angle of inclination of the grinding wheel and the axis of the workpiece. Figure 2 shows the dependence of the shape index p of the raceway profile on the angle of inclination of the circle (d.h. v / a anHbix j.

ilbi y, 3; O..OM il. ICH-FOODS circle. KEZA Percent ng: dog wheel is considered to be acceptable in gzoma jjpeHH .oi i, if this wear is exceeded, the grinding wheel will often change. (2).

As shown in Figs. 1.J and 4, with increasing angle of inclination of the circle r, the profile error increases. With increasing d, the shape index p of the part profile also decreases. However, this change is significant within the inclination angle s / from 4 to 20 °. At 70 °, the shape index changes slightly, d the shape error D increases substantially. Therefore, such values ((. Are irrational. At a 5 °, the indicator slightly differs from that which occurs during normal grinding without grinding a wheel, and therefore, where the values are also irrational. Thus, it is advisable to limit the inclination of the grinding wheel within 5 20J

(Gg1 oropev A.V., Shaposhnik RK Grinding and lapping of external spherical surfaces by the intersecting axis method - Abstracts of the All-Union Scientific and Technical Conference Modern Ways to Increase Productivity and Accuracy of Metal-Cutting Equipment and Automation of Technological Processes in Mechanical Engineering. M .: MDNT.P .. 1980.

Claims (1)

The claims METHOD FOR PROCESSING SHAPED SURFACES OF ROTATION, in which the axis of the grinding wheel with a toroidal working surface is set at an angle to the plane of the longitudinal section of the part and the circle and the part are rotated around their axes, and the circle is supplied with a feed, characterized in that, in order to improve quality and expand technological capabilities due to the processing of both internal and external shaped over Orlov A.V. Rolling bearings with complex surfaces. M.: Science, 1983. p. 114-119. USSR copyright certificate N: 563272. cl. 24 V 19/06. 1972. axes, grinding wheel axes and parts are set in parallel planes based on the condition that the point of intersection of the part axis and the projection of the wheel axis on the plane of the longitudinal section of the part in the plane of symmetry of the latter are positioned, while the working feed is carried out along the shortest distance between the axis of the wheel and the part and the angle between the axis of the circle and the plane of the longitudinal section of the part is chosen equal to 5-20. Bg.1 ugpf you 9160002 FIG. 5 Fi.6