SU1328071A1 - Method of turning inner surfeaces of revolution with cutting tool - Google Patents

Abstract

The invention relates to the machining of metals by cutting and can be used when bore internal surfaces of rotation. The aim of the invention is the expansion of technological capabilities by processing composite blanks of various materials in one set. For this, the processing is carried out with a chisel, which is mounted in a rotating mandrel with the possibility of radial movement and springed against the axis of the mandrel. During the processing, the frequency n of rotation of the mandrel is changed and selected from the dependence n (1: 2; Hk)) | P: t, where R is the radius of the surface to be treated ;, Pn is the radial component of the cutting force; m is the mass of the cutter. 2 Il. sl with so 00

Description

The invention relates to metal cutting and can be used for bore internal surfaces of rotation.

The aim of the invention is the expansion of technological capabilities by processing composite blanks and various materials for one statutes.

Figure 1 shows the scheme is implemented;; The method is twining when boring composite workpiece; figure 2 - the same, when processing the chamfer on the back side of the holes of the workpiece.

The essence of the method is as follows.

In the mandrel 1 mounted on the movable sleeve 2 cutter. 3 and spring it to the axis of the mandrel 1 by means of a spring 4 located between the sleeve 2 and the nut 5. The cutter 3 thus has the possibility of radial movement relative to the mandrel 1

The pin 6, fixed in the movable sleeve 2 and located in the groove of the mandrel 1, limits both the possibility of rotation of the movable sleeve 2 relative to the mandrel 1, and the magnitude of its radial movement. The spring 4 is chosen with a slight stiffness necessary only to overcome the friction force when moving the sleeve 2 with the cutter 3 in the hole of the mandrel 1.

In processing, the tool without rotation is supplied to the composite workpiece being machined, consisting of parts 7 and 8, made of materials with different mechanical properties. When this mandrel 1 have coaxially with the hole of the workpiece. When the tip of the cutter 3 reaches the top end of the hole being machined, the mandrel 1 is reported to rotate with the speed n and the axial flow S, Under the action of centrifugal force, the cutter 3c with the sleeve 2 and the pin 6, compressing the spring 4, moves relative to the mandrel in the radial direction to the wall holes of the workpiece and produces it processing. The frequency of rotation n of the mandrel 1 is set in accordance with the value of the radial component P of the cutting force according to

.

i

0

five

0

5 o

five

0

five

0

five

where R is the radius of the treated surface;

m is the mass of the cutter 3 with sleeve 2 and pin 6 (i.e. moving parts of the tool).

In turn, the radius component Ru of the cutting force is determined by the required values of the depth of cut (in accordance with the allowance for processing) and feed S, the mechanical characteristics of the material being processed in part 8 of the workpiece, etc. by the known formulas of the theory of metal cutting.

At the end of the processing, the holes in part 8 of the workpiece at the moment of transition to its part 7, which is characterized by other mechanical properties of the material (i.e., at the interface), change the frequency of rotation of the mandrel 1 and set it equal to n, (Fig. 1). The indicated frequency value is determined by the above relation (1) in accordance with the new value of the radial component Py of the cutting force due to a change in grade (mechanical characteristics of the material being processed). This allows, at the junction of parts 7 and 8, of the workpiece not to have, after processing, a differential diameter (the so-called step), which is unavoidable with known processing methods.

Subsequently, at the end of the machining of the aperture, the rotational speed of the mandrel 1 is once again changed (increased) to the full depth and is set equal to n (Fig. 2). The indicated frequency value is also determined by the above indicated dependence (1) in accordance with the new radial component P. of the cutting force due to a change in the depth of cut — the formation of a chamfer of the required parameters.

The rotation of the mandrel 1 with the frequency nj is carried out without an axial feed S.

At the end of the complete machining cycle, the rotation of the mandrel is stopped and freely withdrawn from the machined hole to its original position. In view of the cessation of the centrifugal force, the cutter 3 moves with the sleeve 2 from the force of the spring 4 to the axis of the mandrel and does not prevent its exit from the hole of the workpiece.

The proposed method, therefore, has wider technological capabilities in terms of space.

machining holes in workpieces with varying mechanical properties along the length of the machining and chamfering in the holes on their reverse side.

Claims (1)

Formula isotop. The method of turning internal surfaces of rotation with a chisel, which is mounted in a rotating mandrel with the possibility of radial movement and springed to the axis of the mandrel, which differs in that in order to expand the technological 3 15 28071 by machining co-blanks of various materials in one setting, in the process of t-machining, at the point where the tool goes from one section of the workpiece to another, the frequency n of rotation of the mandrel is changed and it is selected from the relation  p - il5l.R I m where R is the radius of the treated surface; R, j - radial component cutting forces; m is the mass of the cutter. 8 1 53