RU2244608C1 - Method and apparatus for determining shrinkage factor of cuttings - Google Patents

Abstract

FIELD: metal working, namely turning processes, possibly determining deformation values of cut layer at metal cutting.

SUBSTANCE: apparatus is in the form of hollow cylindrical vessel filled with liquid and arranged vertically. Piston is mounted inside said hollow cylindrical vessel. There is annular protrusion on inner surface of vessel; said protrusion is designed for engaging with piston end. Piston mounted with possibility of motion along axis of vessel has recess designed for placing in it piece of cutting. Lid having opening is mounted in upper part of vessel for closing it fluid-tightly. Vessel is communicated through flexible pipe with vertically arranged glass tube having capillary opening. Graduated dial is formed on tube for reading liquid level in capillary tube. Method comprises steps of turning blank in machine tool while setting values of cutting depth and feed; cutting off layer of material from blank for converting it to cuttings; then separating part of cutting and placing it in vessel filled with liquid; measuring liquid volume displaced to capillary tube from vessel by means of part of cutting; determining shrinkage factor of cutting according to given formula.

EFFECT: enhanced accuracy and reliability of determining shrinkage factor of cuttings, simplified measuring process.

3 cl, 8 dwg

Description

The invention relates to the field of metalworking and can be used to determine the deformations of the shear layer when cutting metals.

A device for measuring shrinkage of chips, consisting of two parts: a permanent housing and an adjustable housing that install and fasten relative to each other using a screw [A.S. 404609 USSR, B 23 Q l5 / 00. Device for measuring shrinkage shavings / Ivy Yu.A. - No. 1746199 / 25-8, Decl. 02/08/72; Publ. 10/22/73, Bull. No. 44 (prototype)]. The housings are provided with recesses in which the glass tubes are placed. Glass tubes are filled with machine oil at one level, determined by the divisions of the scale applied to the housings. Glass tubes are fixed with a screw and provided with tips. The rubber seal ring is designed for sealing, and fixes the glass tubes in a predetermined position, and does not allow oil to pass from the tips in the housings. Balls are installed in the tips with the possibility of rotation and contact with the chips and the machined surface, when turning. The ball installed in the tip of the permanent body is brought into contact with the surface of the chip, and the ball installed in the tip of the adjustable body is brought into contact with the surface of the workpiece. When the balls rotate, the oil in the glass tubes is consumed. Since the speed of movement of the ball on the surface of the chips and the machined surface (workpiece) is not the same, the oil flow in the tubes varies. Indications of the level of residual oil in the tubes are taken from the left and right parts of the scale. Chip shrinkage coefficient is defined as the ratio of the number of divisions on the left side of the scale to the number on the right side of the scale.

However, this device does not allow with sufficient accuracy and reliability to measure the shrinkage coefficient of the chips due to the fact that the vibrations accompanying the cutting process lead to intermittent contact of the balls with the surfaces of the workpiece and chips. Cases with open tubes filled with oil must be tilted during measurements, which leads to the possibility of oil spills and difficulties during operation. It is also difficult to simultaneously touch the balls of two surfaces (workpiece and shavings) moving with different dynamics, moreover, with the formation of articular shavings, its speed is periodically changing, which also reduces the accuracy of measurements.

A known method of determining the coefficient of shrinkage of the chips, in which the workpiece is installed on the machine, the cutting depth t and feed S, is turned by cutting from the workpiece the layer of the processed material turning into chips, and the chip segment is separated. Measure the length of the chip segment l _ctp and weigh the chip segment on the scales [Mashevich Z.A. Fundamentals of the doctrine of metal cutting and cutting tools. - Mashgiz, 1957: p. 58-61]. The shrinkage coefficient of the chips is calculated by the formula:

where l ₀ is the path length traveled by the cutter during cutting, mm;

l _p is the length of the chip, mm;

f _ctp is the cross-sectional area of the chips, mm ² ;

f is the cross-sectional area of the cut layer, mm ² ;

V _p is the volume of the chip, mm ³ ;

t is the cutting depth, mm;

S - feed, mm / rev;

g is the weight of the chip, g;

γ is the specific gravity of the processed material, g / mm ³ .

To determine the specific gravity of the processed material γ, a sample of the material is usually made in the form of a cylinder, the sample is weighed on the scales, and the weight of the sample g _{about is determined} . Next, measure the diameter D _{about the} height l _{about the} sample and calculate its volume by the formula:

where D _about - the diameter of the sample, mm;

l _about - the height of the sample, mm

The specific gravity of the sample material is calculated by the expression:

where g _about - the weight of the sample, g;

V _about - the volume of the sample, mm ³ .

However, this method does not allow with sufficient accuracy to determine the coefficient of shrinkage of the chips due to the accumulation of errors that occur when weighing the length of the chips and the sample, when measuring the dimensions of the sample and when determining the specific gravity of the material of the sample.

The problem to which the claimed invention is directed is the development of a technology for determining the shrinkage coefficient of chips.

When implementing the invention, the task is solved by achieving a technical result, which consists in increasing the accuracy and reliability of determining the shrinkage coefficient of the chip, by eliminating the unstable contact of the balls with the surfaces of the workpiece and the chip during turning, eliminating the weight of the chip, eliminating the manufacture of the sample, eliminating the measurement of its size, excluding weighing and determining the specific gravity of the sample, as well as the use of a capillary to increase the accuracy of measuring liquid volume ty.

The specified technical result for the object - the device is achieved by the fact that in the device for determining the shrinkage coefficient of the chip containing filled with liquid and installed in a vertical position container in the form of a cylinder, the inner surface of the container is equipped with a ledge designed to interact with the end face of the piston installed in the container with the possibility moving along its axis. Moreover, the piston is equipped with a recess designed to accommodate a piece of shavings in it. In the upper part of the tank there is a hermetically closing lid. The lid is equipped with a tip with a hole on which the end of a flexible tube is fixed, designed to pump liquid from a container into a vertically mounted glass tube. The glass tube at the bottom is equipped with a tip on which the other end of the flexible tube is fixed. The hole in the tube is made in the form of a capillary, and a calibrated scale is applied to the tube.

The specified technical result for the object - the method is achieved by the fact that in the method for determining the shrinkage coefficient of the chips when turning on the machine with the set values of the cutting depth and feed, the layer of the processed material turning into chips is cut from the workpiece, the chip segment is separated and its length is measured. Measure the volume of the chip segment and determine the coefficient of shrinkage of the chip by the expression:

where a _p - chip thickness, mm;

and _slice - the thickness of the slice, mm;

f _page - the cross-sectional area of the chips, mm ² ;

f _cut - the cross-sectional area of the cut layer, mm ² ;

d is the diameter of the capillary in a glass tube, mm;

H ₁ - the initial liquid level in the capillary of a glass tube, mm;

H ₂ is the final liquid level in the capillary of a glass tube, mm;

t is the cutting depth, mm;

S - feed, mm / rev;

l _p is the length of the chip, mm

The claimed group of inventions meets the requirement of unity of invention, since it forms a single inventive concept, moreover, one of the declared objects of the group - the device is designed to implement another claimed object of the group - a method for determining the shrinkage coefficient of chips. In this case, both objects are aimed at solving the same problem with obtaining a single technical result.

The advantage of the claimed device and method for determining the shrinkage coefficient of chips is the use of a capillary to improve the accuracy of measuring the volume of liquid displaced from the tank by a chip segment, as well as higher accuracy and reliability of determining the coefficient of shrinkage of chips due to the elimination of errors that occur when weighing chips, measuring dimensions, determining volume and the specific gravity of the sample material.

The device and method are illustrated by drawings, in which Fig. 1 shows a general view of the device, Fig. 2 and Fig. 3 show the fastening of a flexible tube to the tip of the container lid and a glass tube, Figs. 4-8 show a sequence of operations for determining chip shrinkage coefficient using a device to determine it. The arrows in Figs. 4-7 indicate the direction of movement of the piston.

The device contains a container 1 in the form of a vertically mounted hollow cylinder filled with liquid 2. The cylindrical inner surface 3 of the container 1 in the upper part is made with an annular ledge 4, which is designed to interact with the end face 5 of the piston 6, which is installed with the possibility of vertical movement along the axis 7 of cylinder 1 The piston 6 is equipped with a recess 8, designed to accommodate a piece of chip 9. In the upper part 10 of the container 1 is installed hermetically closing its cover 11. The cover 11 is provided with a hole 12 going through the tip 13 of the cover 11, on which is fixed the end 14 of the flexible tube 15, designed for pumping liquid 2 from the tank 1 into a glass tube 16 installed in a vertical position. The other end 17 of the flexible tube 15 is mounted on the tip 18 of the glass tube 16. In the glass tube 16 there is a through hole in the form of a capillary 19 of diameter d. A calibrated scale 20 is applied to the glass tube 16, designed to read the level of liquid 2 in the capillary 19.

The method of determining the coefficient of shrinkage of the chips using the device is as follows.

The workpiece is installed on the machine, the depth of cutting t and the feed rate S are set. When turning, a layer of the processed material turning into chips is cut from the workpiece. The chip segment 9 is separated and its length l _{cmp is} measured. A liquid 2 is poured into the container 1, which is installed in an upright position, from above the container 1 is hermetically sealed with a cover 11. To the tip 13 of the cover 11, the end 14 of the flexible tube 15 is connected 15. The other end 17 of the flexible tube 15 is fixed to the tip 18 of the glass tube 16. Manual or other in a known manner, move the piston 6 to its highest position (position A ₁ ) (see Fig. 4) until the end face 5 of the piston 6 contacts the step 4 of the container 1, while the liquid 2 is pumped through the flexible tube 15 from the container 1 into the capillary 19 of the glass tube 16. Produce nacha A complete reading of the level H _{1 of} liquid 2 in capillary 19 on a calibrated scale 20 of glass tube 16 (see Fig. 4). The piston 6 is withdrawn to its lowest position (position A ₂ ) (see Fig.6). In this case, the liquid 2 is pumped out from the capillary 19 of the glass tube 16 through the flexible tube 15 into the container 1. The cover 11 is removed and a piece of chip 9 is placed in the recess 8 of the piston 6 filled with liquid 2 (see Fig. 6). The container 1 is sealed with a cover 11 and the piston 6 is moved a second time to its highest position (position A ₃ ) (see Fig. 7) until the end face 5 of the piston 6 contacts the step 4 of the container 1. In this case, the liquid 2 is pumped through the flexible tube 15 from the container 1 into the capillary 19 of the glass tube 16. A re-reading of the level of H ₂ liquid 2 in the capillary 19 of the glass tube 16 is made on a scale of 20 (see Fig. 7). The shrinkage coefficient of the chips is determined by the expression:

where d is the diameter of the capillary, mm;

H ₁ - the initial liquid level in the capillary of a glass tube, mm;

H ₂ is the final liquid level in the capillary of a glass tube, mm;

t is the cutting depth, mm;

S - feed, mm / rev;

l _сmp - the length of the chip, mm.

This implementation of the method for determining the shrinkage coefficient of the chips and the device for its implementation due to the elimination of errors arising from the dynamic contact of the balls with the surfaces of the workpiece and the chips when weighing the chips, the exclusion of size measurements, the need to determine the volume and specific gravity of the sample material, and also due to the use of a capillary for improving measurement accuracy, improves the accuracy of determining the shrinkage coefficient of the chip.

Claims (3)

1. A device for determining the shrinkage coefficient of the chip, containing a glass tube filled with liquid with an opening, characterized in that it further comprises a container filled with liquid and installed in a vertical position, the inner surface of which is provided with an annular protrusion in the upper part for interaction with the piston end installed in the tank with the ability to move along its axis, and the piston is equipped with a recess designed to accommodate a piece of shavings in it, and in the upper part Part of the container has a hermetically closing lid provided with an opening, the container being connected via a flexible tube to a vertically mounted glass tube in which a hole is made in the form of a capillary, and a calibrated scale is applied to the tube. 2. The device according to claim 1, characterized in that the container is made in the form of a cylinder. 3. A method for determining the shrinkage coefficient of shavings, in which when turning on a machine, with the established values of the cutting depth and feed, a layer of the processed material turning into shavings is cut from the workpiece, a piece of shavings is separated and its length is measured, characterized in that the device according to paragraphs .1 and 2, in which the chip segment is placed in a container filled with liquid, the volume of liquid displaced into the capillary from the tank by the chip segment is measured, and the chip shrinkage coefficient is determined by the expression:

where d is the diameter of the capillary, mm; H ₁ - the initial liquid level in the capillary of a glass tube, mm; H ₂ is the final liquid level in the capillary of a glass tube, mm; t is the cutting depth, mm; S - feed, mm / rev; l _p is the length of the chip, mm

Images