SU1763104A2 - Method of machining crankshaft-type pieces - Google Patents

Abstract

Use: machining, machining parts such as crankshafts. The essence of the invention: the processing is carried out by a tool in the form of a disk divided into two sectors. In the first sector there is a group of peripheral cutting elements arranged in accordance with the removal pattern of the allowance from the cylindrical surface of the neck. In the second sector with the same angular pitch are placed the end cutting elements for machining the side surfaces. At the stage of machining the side surfaces of the cheeks, the parts report a rotation corresponding to the circular feed rate, which, after coming into contact with the cheek of the end-cutting member, is changed to a certain value, which is determined by mathematical dependence. With such an angular velocity, the part rotates until the end cutting element comes in contact with the cheek, which is located after the group of peripheral cutting elements. Thereafter, the rotational speed of the preform is restored to its original value. 4 il. sl C

Description

The invention relates to the field of metal cutting and can be used in the processing of parts such as crankshafts and is an improvement of the invention according to the author. St. No. 1421473.

The purpose of the invention is to increase productivity when processing a shaft with an increased width of necks.

The goal is achieved by providing a uniform load between the individual cutting edges, which allows to stabilize the cutting process and, accordingly, to process at higher cutting conditions.

Fig. 1 shows the layout of the part and tool during machining.

side surfaces of the crankshaft cheeks; FIG. 2 is a view A of FIG. one; in fig. 3 is a diagram of the arrangements of the part and the tool when machining the crankshaft; in fig. 4 is a view B in FIG. 3,

The method is carried out as follows.

The billet (crankshaft) 1 is fixed in the chucks of the machine tool and is told to move along a circular path with a frequency of rotation of the axle around the From axis. The tool 2, mounted on the tool spindle of the machine 3, is reported to rotate with the frequency pi (cutting movement) about the axis 02 and the movement S0 in the direction perpendicular to the axis of rotation of the tool.

vj o

SA)

about

Yu

The tool is a disk divided into two sectors. In sector I, there is a group of peripheral cutting elements 4, the radius of which is set out in accordance with the scheme for removing the seam allowance of the cylindrical surface of the neck.

In sector II with the same angular pitch, the face cutting elements 5 are placed. The angle between the face cutting elements located before and after the group of peripheral cutting elements pi. The crankshaft is machined in two stages.

1. Processing side surfaces 6 and 7.

In this case, the machining allowance is removed with the help of the cutting elements 5 located on the end surfaces of the tool.

2. Treatment of the neck 8.

In this case, the allowance from the cylindrical surface of the neck is removed with the help of cutting elements 4 located on the peripheral surface of the tool.

To do this, cut off the radial feed So, rotation of the tool and the workpiece, turn the tool to the position of rotation and move it in the direction of the axis of rotation of the part From by the amount of penetration. Parts and instrument reported simultaneous rotation with the frequencies of PD and PI. Moreover, the speed of rotation of the part corresponds to the cutting speed, and the speed of rotation of the tool - a circular feed.

At the first stage of processing (i.e., processing the side surfaces of the cheeks), the parts report a rotation corresponding to the speed of the circular feed of the front part, which after contact with the processed cheek of the end cutting element located in front of a group of peripheral cutting elements, is changed to

 - front. With such an angular speed

9

the hoist is rotated until an end cutting member follows the group of peripheral cutting elements. Thereafter, the frequency of rotation of the part is restored to the original value of the front part. This cycle of changing the frequency of rotation of the part is repeated until the entire stock of the machined cheek is removed.

Due to this, despite the uneven distribution of the face cutting elements around the circumference,

uniform load distribution on individual cutting edges.

The foregoing can be justified as follows.

In order to have a stable cutting process, it is necessary to ensure the constancy of the cut parameters on all face cutting elements (with their non-uniform distribution). The cut parameter is the product of the width of the layer to be cut by the maximum chip thickness b amax. When machining the cheeks, the cutting width for different end elements is usually the same. Therefore, to ensure equality of the parameters of the slice, it is necessary to ensure the condition

aimax 32max, (1)

where aimax is the maximum chip thickness, removed by equally spaced cutting elements,

32max is the maximum thickness of the chips removed by the end cutting element located after the group of peripheral incisors.

For evenly spaced end cutting elements, the maximum chip thickness is:

aimax - f (Rn + RA - So) sin in, (2)

Pi

where gp is the frequency of rotation of the part;

Pi - tool rotation frequency;

f-angle between equally spaced face cutting elements;

RH is the radius of the circle on which the tops of the end cutting elements of the tool are located;

The poison is the radius of the workpiece;

So - feed per revolution of the part in the radial direction;

in-contact angle (angle of rotation of the rotating tool, necessary for cutting his tooth into the entire depth of the removed allowance).

For the face cutting element located after the peripheral cutting edge group, the maximum chip thickness is equal;

Front e2tah

01 (Rn +) sin in (3)

PI

Substituting the values of aimax and e2x from (2 and (3) into (1), after conversion we get

Iu

front - front JL

Claims (1)

The invention The method of processing parts such as crankshafts auth.St. No. 1421473, characterized in that, with the aim of increased productivity when machining shafts with an increased width of necks, when machining side surfaces of the cheeks at the exit of the cutting elements, placed on the end surface of the tool in front of the elements on the peripheral surface, the frequency of rotation of the workpiece is changed to I P A- # Pagde Pd - the frequency of rotation of the part in the specified area; PD - the frequency of the parts when processing cheeks; L Vida 0 p is the angle between the cutting elements on the end surface;  - the angle of the cutting elements on the peripheral part of the tool, and at the entrance of the cutting elements on the end surface, placed after the cutting elements on the peripheral part, the rotational speed of the workpiece is restored to its original value. 7 1 FIG. 2 ABOUT, Of 2 FIG. B