RU2323066C2 - Ring blanks with two coaxial different-orientation cone openings working method and apparatus for boring - Google Patents

Abstract

FIELD: working metals by cutting, manufacture of bearing assemblies, namely working them in lathes or in multi-spindle semiautomatic lathes.

SUBSTANCE: method comprises step of simultaneously working outer cylindrical surface, two ends and mounting chamfers in the same one position after one mounting; then simultaneously boring generatrices of two different-orientation cones after other mounting operation. Apparatus for simultaneously boring two coaxial different-orientation cone openings in the same position includes cutter unit having grooves for two boring cutters and mounted in holder carrying it. In order to provide mark-free outlet, said grooves for two boring cutters are coaxial ones; cutter unit is made with possibility of forced rotation around axis laid normally in axial straight line of neck cross section of blank and spaced by distance determined according to given relation.

EFFECT: improved efficiency and accuracy of working.

8 cl, 4 dwg

Description

The present invention relates to the field of metal working by cutting parts of a class of rings and can be used mainly in the bearing industry for turning piece blanks for the outer rings of roller conic bearings of a number of series according to GOST 6364-78, GOST 8419-75 and other technical specifications, as well as other machine-building enterprises of the Russian Federation.

A known method of turning rings from piece blanks with two coaxial multidirectional conical holes in two operations performed on two single-index multi-spindle turning semiautomatic devices (MTPA) - [6], adopted by the authors as a prototype.

In accordance with the specified method, complete turning of piece blanks is carried out in the following sequence of operations:

- first, on the first six-spindle MTPA, the workpiece is based on one of the ends in the chuck and is fixed on the outer cylindrical surface, and then sequential processing of one half of the ring surfaces in different positions is performed - boring the inner cylindrical girdle, turning the half of the outer cylindrical surface in two positions with trimming the first the end and removing the mounting (radius) and non-mounting (flat) chamfers in one of them, the bore forming the first cone in two positions.

Turning of the surfaces of the second half of the ring blank is carried out on the second MTPA in the same sequence of positions and transitions as on the first MTPA, but with basing on the first machined end and fastening on half of the machined outer cylindrical surface.

The specified method is used in the same sequence of transitions for processing workpieces with a diameter of up to 200 mm on MTPA and over 200 mm on universal turning machines.

The disadvantages of the method include:

1. The presence of a "step" on the outer cylindrical surface as a result of two workpiece installations caused by the runout of the surfaces of the chucks;

2. The low quality of the relative position of the machined surfaces caused by the two settings of the workpieces, and the accuracy of processing;

3. The presence of helical risks on the treated surfaces of the forming cones as a result of the removal of elastic deformations of the AIDS nodes (systems - fixtures, tools, parts) when the cutters are removed from the treatment zone.

These shortcomings lead to the need to increase allowances for subsequent grinding operations of the surfaces of the ring, and therefore, increase the complexity of processing.

In addition, according to the applicant, the use of two expensive MTPA is irrational, which leads to an increase in the cost of processing.

A number of new designs of clamping chucks are also known, which allow the installation and fastening of ring blanks along two coaxial multidirectional conical holes (see, for example, Sudin Yu.A. Progressive technological processes for turning the outer rings of tapered roller bearings. - M .: NIINAvtoprom, 1985, fig. 12a, b, c, d):

- the design of the cartridge (Fig. 12 a) cannot ensure reliable installation and fastening of the workpieces due to the presence in them of errors of deviations in the angles and diameters of the cones; and did not find application;

- cartridge designs (Fig. 12 c, d) are complex and time-consuming to manufacture, operate;

- the design of the cartridge (Fig. 12 b) [4] showed in laboratory tests the high accuracy of the workpiece installation in the radial and axial planes, the reliability of fixing, regardless of the errors in its manufacture in the diameters and angles of the cones, was unclaimed by the applicant in the context of restructuring in connection with its elimination (bankruptcy); ring processing methods using this design of a chuck have not been developed; this design of the chuck can be used not only on MTPA, but also on conventional lathes for processing ring blanks within the outer diameters of 200 ... 500 mm.

Also known devices for processing multidirectional pine conical holes (see, for example,

- A.S. USSR No. 722691, B23B 29/02 [1]

- A.S. USSR No. 988462, B23B 29/02, [2]

- A.S. USSR No. 1000159, B23B 29/02 [3]

These devices combine the following imperfections:

- the need for preliminary geometric construction to determine the parameters and dimensions of the adjustment of the cutting tool, its position in the processing zone, which increases the time and cost of preparation of production;

- lack of versatility and low range of size control for processing cones;

- the need to have for each size of the workpiece its own device design, which increases their nomenclature;

- high complexity of manufacturing the device, metal;

- the complexity and high complexity of the setup.

The technical result of the invention are:

- increase productivity by concentrating several surfaces of the workpieces of the rings for processing in one position from one installation;

- improving the accuracy of processing and the relative position of the treated surfaces;

- reduction of allowances for subsequent grinding of the surfaces of the rings;

- depersonalization of the base for subsequent grinding;

- reduction of time spent on production preparation, tooling design;

- decrease in capital investments for turning equipment and its depreciation.

These results are achieved in that:

- for full turning of billets of rings with an outer diameter of up to 200 mm from a piece billet in conditions of serial, large-scale and mass production, two-index multi-spindle turning semiautomatic devices are used, and in conditions of small-scale production simple universal turning machines in the following sequence of operations - first they process the base surfaces - outer cylindrical surface, two ends and mounting (radius) chamfers from one installation in one position using a chuck by A.S. USSR No. 1024174 and method according to A.S. USSR No. 1353581; then the bore of two coaxial multidirectional conical holes from one installation in one position using the proposed device design.

The invention is illustrated by sketches, which show:

- figure 1 - the shape of the cross sections of the outer rings of tapered roller bearings manufactured according to applicable State standards and special specifications;

- figure 2 is an example of a proposed scheme for processing billet rings with two coaxial multidirectional conical holes on a two-index 6-spindle MTPA;

- figure 3 is a device for simultaneously boring two coaxial multidirectional conical holes;

- figure 4 is a design diagram for determining the setup parameters of the device for boring and the dimensions of the workpiece blanks rings 97218-21, made on a 1: 1 scale.

The calculations determined the setup parameters:

- the inner zone to accommodate the cutting, auxiliary tools, etc. with the diameter of the throat section formed by the continuation of the forming cones;

- the distance between the vertices of the incisors in the block in a direction parallel to the axis of the throat section (feed);

- the adjustment size of the diameter of the setting of the incisors at their vertices in the block;

- the size of the position of the axis of rotation of the block of cutters for an uncontrolled withdrawal from the processing zone.

To implement the method on a two-index six-spindle turning semiautomatic device (see figure 2), pos. 5 install a piece blank of the ring, base it and fix it with cams along two conical holes; by rotation of the spindle drum, the fixed workpiece is transferred to position 1, on which the bases are pre-treated - the outer surface is cut with a longitudinal support and simultaneously with two cutters from the transverse support, two ends of the workpiece are cut; after which the workpiece is transferred to position III, where the same surfaces are finished, and the mounting (radius) bevel is further grinded and the inner flat bevel is bored; according to this scheme, blanks for rings are processed according to GOST 8419-75 (see Fig. 1-1); for rings in accordance with GOST 6364-78 (see Fig.1-2) in pos. 1 on the outer cylindrical surface along the axis of the cross section of the workpiece, a groove is drilled from the cross support, and in pos. III or pos. IV, a lubricant groove is machined with a shaped cutter ( marked with an asterisk). At the end of the processing, the workpiece is unfastened in pos. 5 and reinstalled in pos. VI, based on any of the processed ends of the workpiece, fixed on the outer cylindrical surface; in pos. 5 fix a new ring blank.

In pos. II, a preliminary boring of two coaxial conical holes is made and a mounting (radius) chamfer is machined; in pos. IV, the fine boring of conical holes and the inner flat bevel are produced, after which the processed ring is removed from the machine.

After boring the inner cylindrical girdle after processing the ring at MTPA, they are produced on a simple universal lathe.

In the processing diagram (figure 2), the position of the cutters is indicated at the end of the working stroke of the longitudinal and transverse calipers of the machine.

Turning of ring blanks with an outer cylindrical surface diameter of 200 ... 500 mm with tool settings similar to poses I and II for MTPA can be applied on single-spindle multi-cutter semiautomatic machines or universal turning machines.

A device for simultaneous boring of two coaxial multidirectional conical holes in one position consists of a holder 1 (Fig. 3) and an integrated cutting unit 2 of a thick steel plate with two coaxial grooves into two coaxial cutters 3 and 4 with the possibility of forced rotation about axis 5 perpendicular to the axial straight line of the throat section at the point of intersection of the straight line segment connecting the initial diametrical points of cutting tools into the workpiece processed at the ends and forming an internal conical erhnosti equal to half, defined by:

the distance between the vertices of the incisors in the direction parallel to the axis of the throat section is determined by the formula:

где

Where

- C ′ ₁ and D ′ _2, respectively, the height and diameter of the large base of the cone of the workpiece after processing its ends;

and the setup size of the diameter at the tops of the cutters with the dependence:

The cutting unit 2 is made in the form of an equal arm, spring-loaded with two stops with spherical ends in contact with the rear radius surface of the unit - one (upper) 6 movable, the other (lower) 7 adjustable with a rod 8 integrated into it, connected to the piston of the hydraulic cylinder (conditionally not shown). The stops are placed in the holder body, and their axes are removed from the holder axis at different distances and parallel to it; wherein the distance of the position of the axis of the upper stop must exceed at least two to three times the distance from the axis of the lower stop to the axis of the holder; This design of the stops and their location provides reliable pressing of the rear radius surface of the cutting block to the lower stop both at the initial moment of cutting the cutters into the workpiece and for the entire cycle of boring of two conical holes.

The creation of the necessary efforts in the stops is carried out by the same size of the taut calibrated cylindrical compression springs 9 with the help of nuts 10, which are moved at the threaded ends of the rods 8.

The spring 9 in the lower adjustable emphasis 7 simultaneously performs the role of a damper, which returns the piston of the cylinder to its original position after the cutless withdrawal of the cutting unit 2 from the treatment zone.

The upper stop 6 from falling out of the holder 1 is held by a threaded rod 11 screwed into the key groove of the stem 8. The coaxial cutters 3,4 in the coaxial grooves of block 2 are fastened by moving the wedges 12 with screws (not shown) in the radial plane, and adjusting them to size carried out outside the machine using self-locking screws 13 with spherical ends.

To protect against abrasion by the chips of the holder 1 and the chips falling into the groove of its front end, the latter is protected by a L-shaped visor 14, fixed to the holder by screws (not shown), and equipped with a self-locking adjustable stop 15 to prevent possible emergency errors when setting up the unit.

A device arranged outside the machine for simultaneous boring of two coaxial multidirectional conical holes is mounted on the slide, moved in the grooves of the MTPA longitudinal support in positions II and IV, held in position by a rod, one end of which is fixed in the machine bed, and equipped with a rotary device for installation at an angle borings along the reference ring fixed in pos. VI and translated into poses II and IV and a hydraulic cylinder for the implementation of the working feed by a controlled hydraulic system command unit. After that, the reference ring is replaced by the ring blank processed in poses I-III; turning the spindle drum translates into poses II and IV, in which two conical holes are bored simultaneously with the working feed of the device in the direction of the throat section axis.

At the end of the boring, the signal is transmitted to the pistons of the rod drive 8 of the lower stop 7 and the drive of the working feed of the device 1 (not shown) by the signal of the control device controlling the hydraulic conduit, which simultaneously rotate the cutting unit 2 clockwise on axis 5 and bring the device 1 out of the zone processing; the spring 9 of the upper stop 6 is compressed and the rod is recessed into the holder 1. With the withdrawal of the device 1 from the treatment zone, the pressure in the working bodies of the actuators of the lower stop rods and the drive of the working feed of the device is released, and the cutting unit under the influence of the springs 9 of the stops 6 and 7 takes initial working position.

Concrete example

1. The experimental design work by the authors:

1.1. Based on the analysis of the state of the technology for manufacturing the outer rings of tapered roller bearings with two coaxial multidirectional tapered holes in the Russian Federation and abroad, according to the available NTL authors.

1.2. On the software and calculations of the parameters of MTPA adjustment;

1.3. Working drawings for a chuck according to A.S. USSR No. 1024174 for the processing of the ring 97218-21;

1.4. Manufactured and tested in laboratory conditions in 1990, a prototype clamping chuck for processing piece billets of rings 97218-21 in the amount of 25 pieces using A.S. USSR No. 1353581 for the simultaneous processing of two ends and two mounting chamfers with the following results:

- non-parallelism of the ends - 0.025 mm with a tolerance of the current technological process - 0.2 mm;

- the taper of the ends is absent, with a tolerance of 0.1 mm;

- ovality of the outer cylindrical surface (NCP) - 0.08 mm with a tolerance of 0.16 mm;

- NCP runout (non-perpendicularity) over a length of 55 mm to any of the ends - 0.05 mm, with a tolerance of 0.16 mm;

- NCP taper - 0.05 mm, with a tolerance of 0.2 mm;

- the roughness of the treated surfaces - NCP, ends - 20 microns; with a tolerance of 40 microns;

2. Intent: attempt to conclude an agreement on the manufacture of chucks, accessories, etc. according to the authors' drawings and to introduce the method no later than 2008 on the basis of granting the right to an open license (if the application is recognized as an invention) to one of the Russian plants - Moscow Bearing ( MP), Volzhsky Bearing Plant (VPZ), part of the European Bearing Corporation (YPC), Samara Bearing Plant (SPZ).

Using the method and device in the bearing industry of the Russian Federation will allow:

1. To increase the productivity of processing the outer rings of tapered roller bearings with two coaxial multidirectional tapered holes by 1.5 ... 2 times;

2. To increase the quality, accuracy of processing and relative position of the treated surfaces by an average of 3 ... 4 times;

3. To reduce capital costs for the acquisition of MTPA and their depreciation by 1.5 ... 1.8 times;

4. Release a certain amount of MTPA for other purposes.

Information sources

1. A.S. USSR No. 722691. Boring device, Mcl. B23B 29/02, BI No. 11, 03/25/80.

2. A.S. USSR No. 988462. Boring device, Mcl. B23B 29/02, BI No. 2, 01/15/83.

3. A.S. USSR No. 1000159. Boring device, Mcl. B23B 29/02, BI No. 8, 02.28.83.

4. A.C. USSR No. 1024174. Cartridge for securing bearing rings, Mcl. B23B 31/10, BI No. 23, 06.23.83.

5. A.S. USSR No. 1178562. The method of installation of ring parts with tapered holes, V23V 1/00, V23V 31/16, BI No. 34, 09/15/85.

6. The technological process of turning 97218A-21, arch. No. 00462, 1987, developed by AO GP3-15 (prototype).

Claims (8)

1. The method of processing billet rings with two coaxial multidirectional conical holes from a piece billet, including processing on multi-spindle turning semiautomatic devices or lathes, characterized in that to increase productivity by concentrating several surfaces for processing in one position, the accuracy of processing and the relative position of the treated surfaces processing is carried out first simultaneously on the outer cylindrical surface, two ends and mounting chamfers from one installation in one zitsii, and then simultaneously forming the bore two opposing cones with another plant. 2. The method according to claim 1, characterized in that the processing of the outer cylindrical surface, two ends and two mounting chamfers are carried out in a chuck that provides installation, basing and fastening of the ring blanks simultaneously along the two conical holes. 3. The method according to claim 1, characterized in that the closed inner zone for accommodating the cutting, auxiliary tools, chip removal while bore the generatrix of two multidirectional cones is determined by the diameter of the throat section formed by the continuation of the forming cones, according to the formula D ₀ = (D ₂ -C ₁ · tgβ) · cosβ, where D ₀ is the diameter of the throat section; D ₂ - the diameter of the large base of the cone of the workpiece rings; C ₁ - the height of the workpiece ring; β is the angle of the cone of the workpiece. 4. The method according to claim 1, characterized in that in order to reduce the time required for preparation of production, tooling design, simultaneous boring of two cones, a cutter block of two coaxial cutters is used, in which the distance between their vertices in a direction parallel to the throat section axis is determined according to the formula

where C ′ ₁ and D ′ ₂ are, respectively, the height and diameter of the large base of the cone of the workpiece after processing its ends; D ₁ - the diameter of the small base of the cones or the inner diameter of the belt of the ring blank. 5. The method according to claim 4, characterized in that the tips of the cutters in the block lie on a straight line connecting the diametrical starting points of cutting into the workpiece with the machined ends, and the setting size A ₁ for processing both cones is determined by

6. The device for simultaneous boring of two coaxial multidirectional conical holes in the ring blank in one position in the form of a cutting block made of a thick steel plate containing grooves on two boring cutters mounted in its holder holding, characterized in that for the faceless output grooves on two boring cutters made coaxial, and incisal unit is adapted to be forced rotation around an axis perpendicular to the axial line of the throat section of the billet in the region of the ring a _2, equal to n Lovina line segment connecting the starting point diametral incision cutters at the ends of the treated preform ring defines dependencies

7. The device according to claim 6, characterized in that the cutting unit is made in the form of an equal-arm lever, spring-loaded with two stops contacting with the rear radius surface of the unit - one upper movable, another lower adjustable with a built-in rod with a spherical end located in the housing holders at different distances from its axis and parallel to it, with the possibility of forced rotation of the cutting unit at the end of the cones bore by axial movement of the rod in the lower stop by the signal of the control unit for hydraulic or pneumatic drive last. 8. The device according to claim 6, characterized in that the groove of the front end of the holder supporting the cutting unit is closed with a L-shaped visor to prevent chips from getting into it and abrasion of the holder and is equipped with a self-locking adjustable threaded stop to prevent possible emergency errors during adjustment block.

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