SU856756A1 - Hole working method - Google Patents

Description

The invention relates to metal cutting, and can be used in the processing of the matrix of holes netsylindricheskih press tool used in the chemical and pharmaceutical industries and other pro- ⁵ thinking during pressing powdery or granular material, - in machine - to produce small holes in detail taper. ^

There is a known method of processing holes in which a split cylindrical tool is rotated and reciprocally moved to its entire height beyond the surface to be machined along its axis fl].

However, with this method of processing holes in parts, for example, dies, due to the constancy of the rotational speed and speed of the reciprocating motion of the tool, a hole with a conical collapse of insignificant depth at the very end of the part is obtained. Moreover, the size of the taper of the collapse is unstable, which does not meet the requirements for the conical part of the holes of the matrices.

The purpose of the invention is the provision of a conical surface.

This goal is achieved in that the rotation frequency and the speed of the reciprocating movement of the tool is continuously changed, while moving the tool toward the top of the cone, its frequency of rotation is reduced, and the speed of the reciprocating movement is increased in the following relationship:

And where is the speed of the axial movement of the tool at a given time;

z 856756

Nj is the frequency of rotation of the tool at a given time;

k is a coefficient depending on the tool material and $ the workpiece,? tool stiffness and hole diameter;

t ^ · is the time of moving the tool along the conical surface from the base of the coyus to the current position;

η is an exponent characterizing the shape of the curve of the hole surface;

- - - the value characterizing LsG - <

hole taper or slope;

h is the depth of the hole; 20

Ad is the value of the specified camber of the hole, equal to the difference between the maximum and minimum diameters of the hole; 25 b - displacement coefficient, depending on the diameter of the hole.

A continuous change in the rotational speed of the tool (split spring 30) and the speed of its reciprocating movement during the machining of the holes provide different contact times of the tool with the part at various 35 points on the surface of the hole and, therefore, a different amount of metal to be removed.

The proposed processing method can also be implemented with 40 changes in only one of the parameters (rotation speed or speed of the reciprocating movement of the tool).

Figure 1 shows the movement diagram ~ * 5 of the movement of the lapping tool; figure 2 diagram of the change in the speed of lapping depending on time; figure 3 is a diagram of changes in the speed of axial reciprocating movement depending on time; figure 4 is a diagram of the relationship of the speed of the reciprocating movement to the frequency of rotation from time to time. ⁵⁵

The essence of the proposed method is a belt "· is illustrated by the example of machining holes of 4 mm dies made of HVG steel with a hardness of HRC 62-65, a split spring-loaded cast iron lapping on a finishing machine mod. OF-26A until a hole surface R _z 0.1 is obtained using diamond paste according to GOST 16811-71.

A 22 mm high matrix with a pre-polished cylindrical hole is installed on the OF-26A machine for final finishing and obtaining a 1: 100 taper at a depth of 8 mm on one side of the hole. Processing is carried out by rotational and reciprocating movement of a split spring-loaded lapping with its withdrawal beyond the surface to be treated.

During processing, the rotation frequency and the speed of the reciprocating movement of the tool are continuously changed., While moving the tool toward the top of the cone, its frequency of rotation is reduced, and the speed of the reciprocating movement is increased in accordance with formula (1).

For the given case, η = 1, h ⁼ £ 3cG 'b = I <3qtb I = 4 and a = 100, then

V; l00i; +4 Ν 800

The exponent characterizes the curvature of the hole and to obtain a conical inner hole having a linear relationship n = 1. When machining cylindrical holes, the ratio = const 'at a constant value of ¹ machining allowance throughout the cylindrical generatrix of the inner hole. The number of double strokes of the tool is 25-30, depending on the size of the machining allowance. The average speed of the axial movement of the lapping is 3 m / min, and the tool stroke is 50 mm, while the double-stroke time of the lapping is 2 s, and the time of its movement from point d to point 5 (Fig. 1) is 0.16 s.

To obtain a taper at a depth of 8 mm, the contact time of the tool with the part at various points on the surface is changed by changing the rotational speed and the speed of the axial reciprocating movement of the grinding in such a way that when the tool moves from the point Of to the point 856756 ke <T (Fig. 1) the frequency its rotation is reduced from 600 rpm to 120 rpm and the speed of the axial reciprocating movement is increased from 1 m / min to 5 m /. min

At the same time, for a matrix hole diameter of 4 mm, its taper is obtained by reducing the flange tool’s rotational speed from 600 rpm to 120 rpm when moving it from point <5 to point δ with constant constant movement to its entire height beyond the limits of the machined surface along its axis, distinguished by the fact that, in order to ensure obtaining a conical surface, the rotation frequency and the speed of the reciprocating movement of the tool continuously change ^ while the tool is moving

S towards the apex of the cone, its rotation frequency is reduced, and the speed is the speed of its axial reciprocating motion, equal to 3 m / min (figure 2); by increasing the speed of the axial reciprocating motion of the lapping tool from 1 m / min to 5 m / min when it moves from point d to point δ with a constant speed of 200 rpm (Fig. 3), and also by 20 reducing the lapping tool rotation speed from 400 rpm to 160 rpm and simultaneously increasing its axial reciprocating speed. movement from 2 m / min 25 to 4 m / min when moving the tool from point c to point b (figure 4).

The proposed method of processing holes has a number of advantages compared to existing methods, since 30 it allows you to get a wide variety of non-cylindrical holes of small taper with a different shape of curvature of the forming surface due to the combination of the Frequency and E5 parameters of the axial speed of the reciprocating tool a conical hole of considerable depth and low taper directly to up to 40 vodka operations, which reduces processing time and increases it accuracy, and therefore, increases labor productivity.

reciprocating movement is increased in the following relationship:

where V · is the axial velocity of the tool at a given time;

Bc - tool rotation speed at a given time;

k is a coefficient depending on the tool material of the workpiece, the stiffness of the tool and the diameter of the hole to be machined;

tj - time of tool • movement on a conical surface from the base of the cone to the current position;

ri is an exponent characterizing the shape of curvature

openings;

- a value characterizing the conicity of the hole or the angular coefficient;

- hole depth;

- the value of the specified camber of the hole equal to the difference between the maximum and minimum diameters of the hole;

b is a coefficient depending on

Claims (1)

The invention relates to the processing of metals by cutting and can be used in the processing of non-cylindrical holes in the molds of a pressing tool used in chemical and pharmaceutical and other industrial fields in the compaction of powdered and granular materials, in mechanical engineering, for the production of small taper holes. A method of machining holes, in which a split cylindrical tool rotates and reciprocates to its entire height beyond the surface being machined Spines along its axis. However, with this method of machining holes in parts, for example, dies, because of the constant rotation frequency and speed of the reciprocating movement of the tool, a hole is obtained with a conical breakdown of insignificant depth at the very end of the part. In this case, the value of the taper of the collapse is unstable, which does not meet the requirements for the conical part of the holes of the dies. The purpose of the invention is to provide a conical surface. The goal is achieved by the fact that the rotational speed and the speed of the reciprocating movement of the tool are continuously changed, while this while moving the tool towards the apex of the cone, the frequency of its rotation is reduced, and the speed of the reciprocating movement increases in the following relationship: (01., {N V. The speed of the axial movement of the tool at a given time; the frequency of rotation of the tool at a given time; a coefficient depending on the material of the tool and the workpiece; the time of moving the tool along the conic surface from the base of the cone to the current position, the exponent characterizing the shape of the surface curvature of the hole, the value characterizing the taper of the hole or the angle coefficient; the depth of the hole; the magnitude of the specified hole camber is equal to the maximum and minimum diameters of the hole; the offset factor depending on the diameter of the hole. The continuous change in the frequency of tool rotation (split truncated priping) and the speed of its reciprocating movement during hole machining provide a different time of tool contact with the part at different points on the hole surface, and consequently, a different amount of metal to be removed. The proposed processing method can also be carried out by changing only one of the parameters (rotational speed or the speed of the reciprocating movement of the tool). Fig. 1 is a flow chart of the lapping tool; Fig. 2 is a plot of the rotational speed of the lap over time; Fig. 3 is a diagram of a change in the speed of an axial reciprocating movement as a function of time; Fig. 4 is a diagram of the dependence of the ratio of the speed of the reciprocating movement to the frequency of rotation versus time. The essence of the proposed method is based on the example of machining holes 0 4 mm of dies made of HVG steel with a hardness of HRC 62-65, split spring-loaded cast-iron priter on the mod machine. OF-26A to obtain the surface purity of the hole R 0.1 using diamond paste according to GOST 16811-71. A 22 mm high matrix with a pre-ground cylindrical bore is installed on the OF-26A machine for final finishing and obtaining a 1: 100 taper at a depth of 8 mm on one side of the bore. The treatment is performed by rotating and reciprocating movement of the split spring-loaded lap with its withdrawal beyond the surface to be treated. During processing, the rotational speed and the speed of the reciprocating movement of the tool are continuously changed. At the same time, when the tool moves to the cone's top, the frequency of its rotation is reduced, and the speed of the reciprocating movement is increased in accordance with formula (l). For this case, p 1, h - b I a 4 and a 100, V The exponent characterizes the shape of the curvature of the hole and to obtain a conical inner hole having a linear relationship n 1. When machining cylindrical holes, the ratio const at a constant value of processing allowance all cylindrical forming the inner hole. The number of double strokes of the tool is 25-30, depending on the size of the allowance for processing. The average speed of axial movement of the priter is 3 m / min, and the tool travel is 50 mm, while the double stroke of the priter is 2 seconds, and the time it moves from point d to point 5 (figure 1) is 0.16 with. To obtain a taper at a depth of 8 mm, the time of contact of the tool with the part at different points on the surface is changed by changing the rotational speed and the speed of axial reciprocating movement of the ground in such a way that when the tool moves from point fa to point 5 (Fig. And its frequency reduce from 600 rpm to 120 rev / m and increase the speed of axial reciprocating movement from 1 m / min to 5 m / min. At the same time, for the diameter of the die hole of 4 mm, the taperness is obtained by reducing the rotation frequency of the tool nta priter from 600 rpm to 120 rpm when it moves from point d to point 5 with a constant speed of its axial reciprocating movement equal to 3 m / min (fig 2); -accessible movement of the lapping tool from 1 m / min to 5 m / min as it moves from point s to point 5 with a constant rotation frequency of 200 rpm (Fig. 3), and also by reducing the frequency of rotation of the lap-in tool 400 rpm to 160 rpm and at the same time increasing its axial recoil speed. movement from 2 m / m to 4 m / min when the tool moves point c to point b (Fig.4). The proposed method of machining versions has a number of advantages in comparison with existing methods, since it allows to obtain a large variety of non-cylindrical holes of small taper with different shapes of curvature of the generatrix surface due to the combination of parameters of the aeration and speed of axial reciprocating movement of the tool, more It also allows to obtain a conic hole of considerable depth and small taper directly on the vodka operation, which reduces the processing time and increases its accuracy, and edovatelno, increases in labor productivity. The invention of the method of processing holes, in which the split cylindrical tool rotates and reciprocates the postulative movement to its entire height. The surface to be machined along its axis is different from the fact that, in order to impose a conical surface, the rotation frequency and speed the translational movement of the tool is continuously changed; during the movement of the tool at the tip of the cone, the rotational speed is reduced, and the speed of the combat movement is increased in the following relation: ,,). - speed of axial movement of the tool at a given time; - the frequency of rotation of the tool at a given time; k is the coefficient depending on the material of the tool of the workpiece, the rigidity of the tool and the diameter of the hole being machined; the time of moving the tool along the conical surface from the base of the cone to the current position; exponent characterizing the shape of the curvature of the hole; a value characterizing the taper of the hole or the angular coefficient; h is the depth of the hole; d - the value of the specified hole camber, equal to the difference between the maximum and minimum hole diameters; - coefficient depending on the hole diameter. Sources of information that are considered in the examination. USSR author's certificate 034, cl. B 24 B 5/06, 1970 it, sec t 150 200 HVH 300 tt, ceK (D1v t34 Phi1.3 ii, CtK 5 t, Vw / r