RU2677451C1 - Method of milling slotted and keyed grooves on the inner surface of the sleeve using a lathe - Google Patents

Abstract

FIELD: machine building.SUBSTANCE: invention relates to mechanical engineering and can be used for milling slotted and keyed slots on the inner surface of bushings on lathes. On the support of the lateral feed of the lathe, the milling device is installed so that the axis of rotation of the mill is perpendicular to the axis of the height of the centers of the lathe and parallel to the direction of its transverse feed. Dividing head is installed on the machine bed in front of the headstock, in which the self-centering chuck fix the workpiece, while the center of the chuck should coincide with the axis of the height of the centers of the lathe. To install the cutter to the depth of milling using the feed cross-support machine. Using the longitudinal feed of the machine caliper in one or several passes, a longitudinal milling of the groove for the entire length of the sleeve is performed. For milling the next groove, turn the cartridge of the dividing head to the corresponding angle and repeat the previous operation. At the same time for milling grooves using cutters corresponding to the shape of the groove.EFFECT: production of grooves of various profiles and sizes with high precision is provided using widely-used metal-cutting equipment.1 cl, 5 dwg

Description

The invention relates to the field of engineering, in particular, when milling spline and keyways on the inner surface of the bushings. Such grooves are necessary to create splined and keyed joints.

The invention can be used in the manufacture of medium and large spline and keyways in relatively long bushings in small-scale and individual production of equipment, as well as in the repair of general engineering equipment, and the spline and keyways of the bushings can be of any shape.

It is known that in mass and mass production the shaping of spline grooves on the inner surfaces of the bushings is carried out by the pulling method using broaching machines and special broaches, by the chiselling method using slotting machines and special cutters, as well as by the method of cold direct extrusion of grooves using hydraulic presses and special dies with punches for extruding grooves with subsequent mechanical processing of the outer and inner surfaces.

All of the known methods of forming slotted grooves on the inner surfaces of the bushings are not universal and require the presence of a certain amount of expensive special technological equipment and special multi-blade shaped tools (sets of cutters, broaches, cold extrusion devices). All the above equipment and tools require serious economic costs, so their purchase and operation in modern small enterprises, pilot plants and small enterprises for the repair of general engineering products may not be practical.

A known method of manufacturing parts such as splined bushings according to patent No. 2070466, according to which the manufacture of parts such as splined bushings, including receiving the original workpiece with an outer diameter equal to the outer diameter of the finished product and an inner diameter equal to the diameter of the protrusions of the splined hole, as well as subsequent cold extrusion of internal splines at the same time, the shaping of the teeth to the full length is carried out in one technological transition, and the excess metal volume, which is the volume of the slots of the slots, is squeezed into n in the direction opposite to the direction of movement of the punch, in this case, get the length of the workpiece equal to the length of the finished product, and then carry out the machining of the stamped workpiece. The disadvantages of this analogue are:

- the need for special press equipment and a die with a punch (each slotted groove size requires its own tooling), as well as metalworking equipment;

- the need for basic technological operations on various equipment: turning the billet billet, cold extrusion of splined grooves in the billet billet, mechanical finishing of the stamped billet billet;

- relatively low accuracy of the geometric dimensions of the slotted grooves due to incomplete filling of the relief of the punch;

- low technological capabilities of the process due to the impossibility of obtaining long products and large grooves of large size and high profile, due to the emergence of very large friction forces between the workpiece, the matrix walls and the punch, and, as a result, the low resistance of the matrix and punch.

A known method of forming spline grooves according to the certificate of authorship No. 370007, according to which the formation of spline grooves in a pre-prepared hole of a part from hard-to-work materials, slotted grooves are performed on the rod, which is inserted into the hole of the part and rigidly connected to the latter, after which the hole in the rod is bored before opening the slotted grooves, and to prevent chipping of the walls of the grooves at the time of opening when processing parts from brittle material, cavities formed by grooves on the rod and surface Thy parts are filled with fusible material during processing. The disadvantages of this analogue are:

- high complexity of manufacturing;

- additional consumption of materials for the manufacture of a rod with grooves and fusible substances.

The closest analogue to the proposed invention in terms of technical nature and the achieved result is a method of forming spline grooves on the inner surface of the sleeve according to copyright certificate No. 1260169, according to which a tubular workpiece is used as a sleeve blank longer than the required sleeve length and a thickness equal to the sum of the sleeve thickness and height slots, on which preliminary longitudinal grooves are preliminarily performed with a length equal to the length of the sleeve and a width equal to the width of the grooves formed by the splines of the sleeve, where e as a mandrel, use a cylindrical rod with a diameter equal to the inner diameter of the splines, the filling elements are made in the form of rods with a cross section corresponding to the cross section of the sleeve at the location of the grooves formed by the splines, and after removing the mandrel and inserts, a segment of the end part of the tubular workpiece is cut without longitudinal grooves . The disadvantages of this method are:

- high complexity of manufacturing;

- low accuracy of the geometric dimensions of the spline grooves due to welding of the filling elements to the main tubular workpiece;

- additional consumption of materials for the manufacture of a cylindrical rod and liners.

The objective of the invention is to develop a simple, reliable and universal method of forming grooves on the inner surface of the bushings, with a minimum range of used industrial metal-working equipment and tools.

The main technical result, due to which the task is achieved, is to expand the range of sizes of keyways using the minimum amount of metalworking equipment and tools, and to achieve high accuracy of the geometric dimensions of the resulting grooves.

Obtaining the technical result is achieved in the proposed method of milling spline and keyways on the inner surface of the sleeve using a lathe, in which a workpiece is made, the outer and inner diameters of which correspond to the final dimensions of the sleeve, and a milling device is installed on the cross-feed support of the lathe, and the axis the rotation of the cutter should be perpendicular to the height axis of the centers of the lathe and parallel to the direction of its transverse feed. A dividing head is installed on the machine bed in front of the headstock, in the self-centering chuck of which the workpiece is fixed, while the center of the chuck must coincide with the height axis of the centers of the lathe. To set the cutter to the milling depth, use the feed of the transverse support of the machine. Using the longitudinal feed of the machine support in one or several passes, produce longitudinal milling of the groove for the entire length of the sleeve. For milling the next groove, the dividing head cartridge is turned to the appropriate angle and the previous operation is repeated. At the same time, for milling grooves, milling cutters corresponding to the shape of the groove are used.

The use of a lathe in the present invention does not require additional costs for enterprises, since this type of metal-cutting equipment is the most common in modern metal-working production, and the technical characteristics of such equipment allow to obtain high-precision products.

The dividing head is widely used in engineering enterprises. It has high accuracy of angular positioning when machining parts with radially spaced grooves. The dividing head is mounted on the bed of the lathe between the headstock and the caliper.

The milling device is designed for longitudinal milling of slotted grooves by the end mill over the entire length of the sleeve. It has its own high-frequency electric drive, which allows you to adjust the number of revolutions of the cutter, and is installed on the cross feed of the lathe with the standard tool post removed. The device consists of a housing in which a shaft is mounted on the rolling bearings, connected through a coupling to an electric motor. The shaft through a bevel gear is connected to a perpendicularly mounted spindle, in which the cutter is fixed. The body of the milling device is mounted on a regular place of the tool holder of the lathe with a clamp.

Thus, the proposed method of milling grooves on the inner surfaces of the sleeve is universal, as it allows you to produce grooves of various profiles and sizes with high accuracy and at the same time use widespread metal-cutting equipment, technological equipment and tools.

The invention is illustrated by the following graphic figures:

FIG. 1 is a general view of a lathe with a milling device mounted on it with a mill and a dividing head.

FIG. 2 - section aa. The location of the milling device, the workpiece and the mill relative to the axis of the height of the centers of the lathe.

FIG. 3 - section BB. The location of the milling device relative to the height axis of the centers of the lathe and its attachment to the cross feed support.

FIG. 4 - general view of the lathe (top view) with the workpiece, milling device and milling cutter.

FIG. 5 - view G. Installation of the cutter in the milling device relative to the workpiece (sleeve) and the axis of the milling device.

In FIG. 1 and 4 show a lathe 1 with a dividing head 2 mounted on it, a milling device 3, a machined sleeve 4.

The lathe consists of the following main parts (nodes):

- beds 5;

- front headstock 6;

- tailstock 7;

- longitudinal support 8;

- transverse caliper 9.

The dividing head 2 is installed and fixed on the frame 5 between the front headstock 6 and the longitudinal support 8 (Fig. 1). As a dividing head, a dividing head with a vertically located three-jaw self-centering cartridge, supplied by Mash-service, can be used.

The milling device 3 is mounted on the transverse support 9 (Fig. 1) and secured with a clamp 19 (Fig. 3) in a regular place with bolts 10 of the removed tool holder of the lathe 1. The milling device 3 consists of a housing 11 in which the rolling bearings 12 (Fig. 5) a shaft 13 is installed, connected through a coupling 14 (Fig. 4) with an electric motor 15 having a device for high-frequency regulation of the number of revolutions of the shaft 13 (not graphically shown).

The shaft 13 through a bevel gear 16 is connected to a perpendicularly mounted spindle 17, in which the end mill 18 is fixed (Fig. 5). The housing 11 of the milling device 3, through the clamp 19 is installed and mounted on regular bolts 10 of the tool holder of the lathe (Fig. 3).

The method of milling spline and keyways on the inner surface of the sleeve is as follows.

On the lathe 1, a blank of the sleeve 4 is made (Fig. 1), the length of which the outer and inner diameters correspond to the final dimensions of the sleeve.

A milling device 3 is installed on the lathe 1 (Fig. 1), and the axis of rotation of the cutter 21 should be perpendicular to the height axis of the centers 22 (Fig. 5) of the lathe and parallel to the direction of its transverse feed 23 (Fig. 1). The accuracy of the installation of the milling device is determined by the technical requirements of the sleeve drawing.

On the bed 5 of the machine 1 set the dividing head 2 (Fig. 1) in a self-centering chuck 24, which fixes the workpiece of the sleeve 4, while the center of the chuck of the dividing head 2 must coincide with the axis of the height of the centers of the lathe 22 and the axis of rotation of the cutter 21. The accuracy of the installation of the dividing heads are determined by the technical requirements of the sleeve drawing.

Using the longitudinal feed 25 of the machine using the handle 26 (Fig. 1) of the longitudinal support 8, the milling device 3 with the milling cutter 18 installed in the spindle 17 (Fig. 5) bring the milling cutter to its initial position with a clearance of 20, and using the handle 27 set the milling cutter to the required the depth of milling of the groove 23 relative to the workpiece blank of the sleeve 4. Then, the milling device 3 and the automatic longitudinal feed 25 of the machine are turned on and the first groove is milled to the entire length with a technological overrun of the milling cutter 28 (Fig. 5). Termination of the longitudinal feed is carried out by a limit switch (not graphically shown). This operation is repeated until the desired groove depth is obtained.

Then, using the handle 29 of the dividing head 2 (Fig. 4), the workpiece of the bushing 4 is rotated by the required angle and the next spline groove is milled in the reverse direction of the automatic longitudinal feed 25 to the stop with a travel switch (not shown).

Thus, the process of milling grooves continues until the complete production of the required number of grooves in the sleeve.

Claims (1)

A method of milling spline and keyways on the inner surface of the sleeve using a lathe, in which a workpiece is made, the outer and inner diameters of which correspond to the final dimensions of the sleeve, characterized in that a milling device is installed on the cross-feed support of the lathe from the position of the axis of rotation of the mill perpendicular to the height axis of the centers of the lathe and parallel to the direction of its transverse feed, a dividing head is installed on the machine bed, in a self-centering chuck which secures the workpiece from the condition that its center coincides with the axis of the center height of the lathe, while to set the cutter to the required depth of milling of the groove, use the feed of the transverse support of the machine, and perform longitudinal milling of the groove for the entire length of the sleeve using a longitudinal feed to move the milling cutter the machine support, after which, for milling the next groove, the self-centering chuck of the dividing head is turned to the appropriate angle and the previous operation is repeated tion, wherein the grooves are used for milling cutters corresponding to the shape of the groove.

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