UA75010C2 - Shaping cutter for restoring the profile of the wheel rim of railroad rolling stock - Google Patents

Abstract

Shaping cutter for restoring the profile of the wheel rim of railroad rolling stock contains a housing with knives. In the knives, in rows in accordance with the profile line adequate to the profile of wheel rim, the cylindrical cutting plates are mounted. These plates are separated between them by partitions. The thickness of partitions along the profile line of base knife is variable and is determined on the basis of the inequality. In this case, the next knives have the arrangement of the first cylindrical cutting plates with a shift along the profile line for an angular value (i. The first plate of base knife is located in the junction of the profile line of ridge part with the profile line of the internal face of bandage.

Description

Description of the invention

The proposed invention belongs to the designs of special cutters and can be used to restore 2 profiles of wheel pairs without rolling them out from under electric locomotives, diesel locomotives and motorcar sections on wheel-milling machines.

The shaped cutter for restoring the profile of the wheel rim of railway rolling stock is a multi-bladed cutting tool in which the cutting edge formed by discretely installed cutting elements (blades) in the knives is not parallel to the axis of rotation and is a combination of straight and curved lines, but the 70 profile surface of the product is formed as a result of the rotation of the cutting edge. The profile of a shaped cutter is the trace of rotation of its cutting edge relative to the axis of the tool.

Shaped milling, in comparison with the processing of complex curved surfaces by copying, provides higher productivity and low roughness of the processing. The most effective and widespread application of shaped cutters was in turbine construction, the tool industry, and in the rebuilding of rim profiles of 12 wheel pairs of railway transport.

For example, a complex profile milling cutter for processing the profile of the tail of working blades is known (Y.V.

Kudevytskyi. Shaped milling cutters. L., Mashinostroenie, 1978, p.Z41.

The milling cutter consists of a body in which cutting knives and elements for their installation and fastening are fixed. Flat knives are fixed in the grooves of the body with the help of cylindrical pins with a conical lip.

Fixation of the knives is carried out by a key fixed at the bottom of each knife groove in the body of the cutter.

A special feature of the milling cutter is obtaining a continuous cutting edge corresponding to the profile of the processed surface.

A special group consists of shaped cutters with a variable profile shape. The profile of the cutting edge of such a cutter is a set of elementary cutting blades installed according to a profile template, or rectilinear and curved cutting blades installed at a given angle to the axis of rotation of the tool, which allows changing the profile of the cutter within fairly wide limits. Gee)

For example, a prefab shaped milling cutter is known (Y.V. Kudevytskyi. Fasonnye frezyi. L., Mashinostroenie, 1978, pp. 44, 45), which consists of a body into which adjacent knives are inserted into radial grooves. Knives are fixed in the body on a key of a special shape, with the help of which their radial movement during work is excluded and the outer diameter of the cutter is regulated. Knives are fixed with screws and half rings. at

An important positive quality of this cutter is the restoration of the outer diameter of the cutter after its "- resharpening with the help of a set of replaceable keys of a special design.

The design of a milling cutter for restoring the profile of the wheel rim of rolling stock of railway transport is also known (Chetverikov S. S. Metallorezhushchie instrument!. M., Vyissaya school, 1965, p. 246-247). oh

The milling cutter contains a body with knives in which rows of cylindrical cutting plates are installed, located according to the profile line of the milling cutter, which is adequate for the wheel profile. in

Knives are fixed in the case using a wedge and a clamping screw. By rotating the carbide plates as they wear around the axis, the maximum possible use of the cutting circular edge is achieved.

During the period of operation, they can be turned around the axis up to 10 times, in addition, they can be used from both ends. "

As a result, each plate without resharpening works in 16-20 positions. With 70 In the specified constructions of cutters, the necessary technical result is not achieved: a reduction in the roughness of the processing, an increase in the rigidity of the attachment of the plates, their vibration duration and stability.

From" The closest in terms of technical essence and the result that is achieved (prototype) is the design of a shaped cutter for restoring the profile of the wheel of rolling stock of railway transport, which contains a body with knives, in which, in rows, according to the profile line, adequate profile of the wheel rim, cylindrical cutting platinum, separated from each other by jumpers (patent of Ukraine for invention Mo25091 A, IPC 7 6в23С 5/12; В23С 5/14, 19981). 4! A distinctive feature of the milling cutter is that the cutting plates in the adjacent knives are set with a shift relative to each other with a step "" of a variable value within (0.22...0.34) K along five zones of the profile line, where about K - radius of the cutting plate. - 70 The proposed shift interval of the cutting plates ensures optimal overlap with each subsequent cutting element of the processing trace of the previous cutting element, and as a result, sections of the profile with low roughness ("high purity") of the processed surface are obtained. This design is taken as a prototype due to the fact that it has the same purpose as the claimed invention, the commonality of essential design features and has an important quality - the ability to restore the profiled cutting edge as a result of 29 turns of the cutting plates around their axis.

GF) Despite its positive quality, the milling cutter, according to its description in the above-mentioned source, does not contain a solution to such issues as achieving high quality and reliability by using the characteristic features of the construction and operation of the milling cutter. The arrangement of the cutting plates proposed in the prototype with a wide range of their displacement along a conditionally divided profile line into five zones is not rational, because 60 determines different removal of metal by the plate and, as a rule, an uneven load on the edge of the cutting plate, which in turn causes unevenness of stresses throughout the knife and ultimately leads to the destruction of the bridges between the plates and increased wear (destruction) of the plates. In addition to this, the variable step of the location of the plates in the knives leads to uneven roughness, and therefore to a low quality of the processed surface. because In this regard, the basis of the proposed invention is the task of creating such a design of a shaped cutter, in which, by means of a new order of arrangement of cylindrical cutting plates along the profile line of the knife, ensuring the strength and rigidity of the attachment of the plates in the knife, the necessary uniform roughness of the machined surface is achieved and, in as a result, increased processing productivity. At the same time, as a result of taking into account the uniform stress-strain state of the plates and the bridges that separate them from each other, when processing with such a multi-blade tool as a cutter (121-128 cutting plates), a high quality of processing is achieved and the cutting resource of the cutter increases.

To solve the problem, the design of a shaped milling cutter is proposed, which contains features common to the prototype - a body with knives, in which cylindrical cutting plates are installed in rows according to the profile line, adequate profile of the rim 7/0 Wheels, separated from each other by jumpers, which differs in that , that the shaped cutter has a basic knife with variable thickness of jumpers along the profile line of the knife, the thickness of which is determined by the following inequality (1):

TEL. 2 in g 5 ЗХ-- Ж - 8 - - Я -- -5 -- s add "Y where 5; - thickness of the bridge between the ith (Ii-1) cutting plates;

A - the coefficient that takes into account the working conditions and material properties;

Ktvll - radius of the carbide plate, mm;

KE, - acceptable value of roughness of the treated surface, mm;

Phi - the main angle in the plan on the i-th plate of the processed section of the profile line, deg.; 5; - feed per tooth of the i-th plate, mm; c 29 I - cutting depth, mm; Ge) n is an exponent that reflects the influence of the argument on the function; p; - the diameter of the milling cutter on the i-th plate of the processed section of the profile line, mm; odop " permissible normal stress, MPa; o

N; - the height of the jumper between the i-th and (4-1) cutting plates, mm.

In this way, the distance between the cylindrical cutting plates in the base knife is formed, while the first plate on the base knife is located at the point of connection of the profile line of the comb part with the profile line of the inner face of the bandage. at

In the next knife, the first cylindrical cutting plate has an offset along the profile line relative to the first Щ3 cylindrical plate of the base cutting knife, and in each subsequent knife, the first plate has an offset along the profile line relative to the first plate of the previous knife by the angular value со;, determined by the formula (2). - 2 2 (23 b akssov U shity tn; , « - s de o; - angular displacement of the first hole under the carbide plate on the second knife relative to the first (basic

From" knife), as well as each first hole on the following knives in relation to each first hole of the previous knife, degree.;

And - the length of the side of the angle that limits the angular shift of the first hole under the carbide plate on the second 75 knife relative to the first (base knife), as well as each first hole on subsequent knives relative to each first hole of the previous knife, mm. axis The location of other plates in subsequent knives is determined taking into account the inequality (1).

The causal relationship between the new set of features and the technical result is as follows. o In the proposed invention, the formation of the order of arrangement of the cutting cylindrical plates - 70 is carried out in two stages, in which the equivalent tasks of ensuring sufficient strength of the cutting elements of the cutter and obtaining high quality of processing are successively solved, in contrast to the prototype, where the emphasis is on obtaining a high quality of roughness on individual sections of the profile. At the first stage, the stress-strain condition of the plates and the jumpers of the base knife, which separate it from each other during processing, is evaluated. In the jumpers under the action of the resulting cutting force, normal stresses c arise, which, with the determined 59 thickness of the jumper 5 in the base knife, can lead to the destruction of the jumpers. Therefore, the use of the same

ГФ) of the roughness value K, allows to obtain an equivalent nature of the load of the cutting elements of the knife due to the same removal of metal by all cutting plates, and the same value of the permissible normal stress sdop for all jumpers of the basic knife, taking into account their design features, makes it possible to choose such a size of the jumper 5, which will adequately respond to the tensions arising in it. Thus, because the distance between the cylindrical cutting plates in the base knife is determined taking into account the required thickness of the bridge 5 for each section between the two cutting plates, thus ensuring its reliability and, therefore, high processing productivity.

In the following stages, the distribution of cylindrical cutting plates on other knives is carried out relative to the base knife by the angle A, the value of which allows taking into account the design features of all sections of any existing 65 wheel rim profiles through the variable GI value. At the same time, the required uniform roughness K, is preserved, in contrast to the prototype, where the variable step of distributing the plates by zones leads to uneven roughness.

Thus, the new arrangement of the cutting plates provides not only high processing productivity, but also high quality.

An additional technical result - ensuring deliberately high strength of the jumpers and the uniformity of the stress-strain state allows to reduce the vibration of the cylindrical cutting plates during the processing, and the thickness of the jumper allows you to respond adequately to the cutting conditions and creates optimal conditions for the chip guide, thereby increasing the cutting life of the cutter.

The proposed invention is explained schematically in the figures. 70 Fig. 1 - a general view of the claimed shaped cutter;

Fig. 2 - a view of the right to the shaped cutter, which is claimed;

Fig. 3 - a general view of the rail with carbide plates;

Fig. 4 is a cross-section A-A of Fig. 3, which shows the cross section of the bridge 5 in the plane of the normal resultant cutting force;

Fig. 5 - variant of the angular shift on the radius section of the profile;

Fig. 6 - a version of the angular shift on the rectilinear section of the profile;

Fig. 7 - a fragment of the arrangement of carbide cutting cylindrical plates for determining the thickness of the bridge between them;

Fig. 8 - a fragment of the location of the first hole under the carbide cutting cylindrical plate of the next 2o knife relative to the previous ones to determine the angular shift between them;

Fig. 9 - a fragment of the unfolding of the knives in the body of the milling cutter.

The proposed invention has the following construction.

The shaped cutter (see Fig. 1) contains a body 71, in the grooves of which knives 2 are attached. The cutter has a base knife (Fig. 9), the first plate of which is located at the point A of the connection of the profile line of the ridge part with the profile line of the inner face of the bandage (Fig.5 and Fig.b).

Knives are fixed with screws З and breadcrumbs 4, which press the knife according to the bottom and side (8) wall of the groove. At the same time, the end of the knife from the side of the comb must be pressed against the base (left) ring 5.

The left ring 5 and the right ring 6 are attached to the body with screws 7 (see Fig. 2).

Screws 8 (see Fig. 2) are intended for installation of knives on the base ring 5. This fastening ensures precise fixation of the knives in the body of the cutter.

Knives are marked and installed in the correspondingly marked grooves of the case in a strictly defined order. at

In the knives, cylindrical carbide cutting plates 9 with jumpers 10 between the sockets for fastening the cutting plates are installed in rows. o 35 The basic knife has a variable thickness of jumpers along the profile line of the knife (Fig. 7), the thickness of which is determined from the conditions of strength according to the allowable normal stresses occurring in the section normal to the action of the cutting force. ve v y p «

B add z - where c is the normal voltage arising in the body of the jumper; -» R; - the resulting cutting force on the (i-n1) plate is determined | see P.M. Yashcheritsyn, M.L. Eremenko, N.Y.

A lighter Fundamentals of material cutting and cutting tools. Minsk, Higher School, 1981, p. 244) by formula (1.2); - and E; - the cross-sectional area of the bridge between the i-th and (ii-1) cutting plates is determined by the formula "sl (1.5); odop " permissible normal stress. («c) - 70 zara p-va, 2 and where A is a coefficient that takes into account the working conditions and properties of the material, A - Sr.l (P.I. Yashcheritsn, M.L. Eremenko, N.Y. Zhigalko. Fundamentals of cutting materials and cutting instruments. Minsk, High School, 1981, p. 2A61; o B; - the cutting width of the i-th plate is determined by the formula (1.3); k 5.- feed per tooth i- of that plate; p o is an indicator of the degree that reflects the influence of the argument on the function (P.M. Yashcherytsin, M.L. Eremenko, N.Y. 60 Zhigalko. Basics of cutting materials and cutting tools. Minsk, Vyishzhyshaya school, 1981, p. .245);

I - cutting depth;

ABOUT; - - diameter of the cutter at the point of contact with the i-th plate of the processed section of the wheel rim profile (see

Fig. 1 and Fig. 3). b5 B - Tovipfd, (0 where T is the distance between the points of contact of adjacent carbide plates of the wheel rim determined by formula (1.4);

F, - the main angle in the plan on the i-th plate of the processed section of the profile line (see Fig. 3). and vv 33- (14) 7 - the 8. calf. E, -4 "Re, where Ttvll. - the radius of the cylindrical carbide plate;

K, - the value of the roughness of the machined surface, which is allowed (V.A. Arshinov, G.A. Alekseev. Cutting of 70 metals and cutting tools. Moscow, "Mashinostroenie", 1967, p. 63).

B-yr8, 05 /5 de PN; - the height of the bridge between the i-th and (Ii-1) cutting plates;

Z is the thickness of the bridge between the i-th and (4-1) cutting plates (see Fig. 4).

Considering the value of P; and E; from (1.2) and (1.5), the normal stress that occurs in the jumpers between the mounting holes of the cutting plates has the form: ' 1st (1.6) 7 di 1-p pr

A.V. Btvlya B" - 4.2 o vipfo 8; b 2 p - pi t 5 b extra:

On the basis of (1.6), the value of the variable thickness of 5 jumpers along the profile line of the knife is determined by the inequality: сч ч р c) 2 2-8 1

A -liVA tlia Be - 482. Bipf 85; (5) -ЖХ-- - - : - - - - « - I Z Ж : 2 2 - -- -.

The first plate on the base knife is located at the point of connection of the profile line of the ridge part with the profile line of the inner face of the bandage. The following knives have the location of the first cylindrical cutting plates with a shift along the profile line by an angular amount.

Determination of the angular value of the location of the first cylindrical plates B, C, O that cut (Fig. 5 and Fig. b) in the following basic knives is carried out using the theorem of cosines. IS) and - 24

AND? I: -tT2 (21) sobod i --- 2 5 - o t 2.1x where o; - angular displacement of the first hole under the carbide plate on the ith knife relative to the first hole on (1-1) - knives; с И - the length of the side of the angle that limits the angular shift of the first hole under the carbide plate on the i-th knife "" relative to the first hole on the first (1-1) knife (see Fig. 5 and Fig. b); n . . . .

T is the distance between the points of contact of adjacent carbide plates of the wheel rim determined by formula (1.4). -i 2 2 (22) sl sovots- TSO -YAKvlyas, nav; eat («c) -l 20 Thus, the determination of the angular displacement along the profile line of the first cylindrical plates B, C, O that cut (Fig. 5 and Fig. b) in the following basic knives has the form:

Shk in Shchi Yartvlya in av o avsoyatttt

The location of the other plates in the following knives is determined taking into account the previously mentioned inequality.

The cutting plates in the knives are fastened with screws 11 and nuts 12. A spring washer 13 is installed between the nut and the knife, which protects the screw from self-unscrewing. 14 compensating washers of different thickness are installed under the cutting plates, which ensure the accuracy of setting the cutting plates along the profile line of the product contour. The proposed cutter works in the following way. When restoring the wheel profile, the cutting process begins with the cutting of the cutting plates 9 of the knives 10. As the milling cutter and the wheel pair being processed rotate relative to each other, all milling cutter knives come into operation sequentially, removing metal. At the same time, the plates of the cutting knife, starting processing, remove the first layer of metal, then the plates of the adjacent cutting knife enter, shifted to a given angle o, etc. After removing the metal with the plates of the last knife, cutting is completed in one revolution of the cutter. 65 Thanks to this arrangement of the knives, the processing of the wheel profile is carried out along the entire profile with cylindrical cutting plates located along the axial line of the cutter in the corresponding zones.

At the same time, as a result of obtaining optimal conditions for the removal of chips, the wear of the cutting plates and bridges on the knives is reduced, which additionally increases the resource of the milling cutter.

The cutters work in a set of two pieces - right and left, processing both wheels at the same time.

The design of the right and left cutters is similar.

The wheel pair (conditionally not shown) is installed on the wheel-milling machine of the KZh-20 model or its modifications.

Processing is carried out at a constant cutting speed of 60-8Ω/min.

The use of this cutting speed protects the cutters from excessive wear and chipping of the plates. 70 The amount of feed is chosen within 100-150 mm/min.

After processing each wheel pair, the condition of the cutting plates is inspected by turning the milling cutter manually.

Plates with chips are rotated before processing the next pair of wheels.

Before turning the plate, it is necessary to unscrew the nut 12 that secures the plate by 1-3 turns, then use a screwdriver to turn the screw head together with the plate so that the worn part of the cutting edge is /5 Replaced with a new one. When one side of the edge is completely worn, the plates should be removed from the holes of the knives, carefully cleaned and installed in the same holes of the knives with the other side.

A set of cutting plates, when used from both sides without changing the compensating washers 14, provides processing of wheel pairs from 16 to 18 locomotives.

As a result of new changes in the design, the proposed milling cutter allows to increase processing productivity while simultaneously increasing the accuracy and quality of the processed wheel surface, as well as increasing the stability of the milling cutter.

An example of calculating the thickness of the first three bridges of the base knife of a shaped cutter for processing a profile according to drawing C according to GOST 11018-87.

First jumper 53.

Output data: A - 2570; Ktivpl. - bmm; K, - 0.0 mm; F - 28.2 degrees; 5, - 47.5 mm/tooth; ii - 4 mm; O - 168.5 mm; p - sch dv O14; n 111MM; sdod - 790 MPa. at 2570. iv 8.008-4.0082.0473- atm (I ur 812 11111188 g 1bmMm 501

The second jumper 5". -

Output data: A - 2570; Kivpl. - bmm; K, - 0.08 mm; F - 74, Ograd.; Z, - 47.5 mm/tooth; ii - 4 mm; O - 1512 MmM; n ek n 0.14; n - 12.2 mm; sdop - 750MPa. 2570

The third jumper 53.

Output data: A - 2570; Kivpl- bmm; K, - 0.08 mm; F - 48 degrees; 5, - 47.5 mm/tooth; its - 4 mm; OO - 158.1mm; n - 0.14; and - 13.9 mm; pressure - 750 MPa. "2570. (-v.00v-4.0082 opt atdoyav in I times - 70 bra nyny nn I kOm z og s t50.139 :z" Similarly, the thicknesses of all other jumpers on the base knife, as well as on the following knives, are calculated similarly.

An example of calculating the angular displacement of the first hole under the cylindrical carbide plate for the knife of the shaped cutter, adjacent to the basic one. -1 15 Initial data: I. -23.2 mm (for the profile according to drawing Z according to GOST 11018-87); Ktvpl -bmm; K,-0.08 mm. b agsoye2227-4-8-008o oo - 4.8 degrees. ini 23 ' (av) Conclusions. On the example of calculations of the variable thickness parameter of jumpers 5; of the base knife of the shaped shu 20 milling cutter for processing the profile according to drawing Z according to GOST 11018-87 and the angular displacement of the first hole under the cylindrical carbide plate of the knife, adjacent to the base one, in the end result we have a constant 62 normalized roughness (K, - 8Ωm) over the entire profile surface wheel rim

The proposed invention has successfully passed experimental tests.

The formula of the invention

Ф) ko 1. A shaped cutter for restoring the profile of the wheel rim of a railway rolling stock, containing a body with knives, in which cylindrical cutting plates, separated by jumpers, are installed in rows according to the profile line, adequate profile of the wheel rim, which differs in that that the shaped cutter has a basic knife with a variable thickness of bridges along the profile line of the knife, the thickness of which is determined by the following inequality: b5

Claims (2)

1-5, from 1 ru: -her A. VA nal, with K,- HOW ov od yuyu uh and VA - I same 2 same :- - same 4 - - - wl - -ya -d - - zov: y, de 5; - the thickness of the jumper between the i-th and (ii-1) cutting plates; A - the coefficient that takes into account the working conditions and material properties; 70 Etepl. - radius of the carbide plate, mm; E, - permissible value of roughness of the treated surface, mm; фи - main angle in the plan on the ith plate of the processed section of the profile line, deg.; KA - feed per tooth of the i-th plate, mm; th 19 x - cutting depth, mm; n - exponent indicating the influence of the argument on the function; рх - the diameter of the edge on the i-th plate of the processed section of the profile line, mm; I c dop - permissible normal stress, MPa; n - the height of the bridge between the ith and (4-1) cutting plates, mm, while the following knives have the location of the first cylindrical cutting plates with a shift along the profile line by an angular value s, determined by the formula: 2 -ativdya B. NEW s soy -atssov-- 5 ( 5 - 4 - 5 - yat i; where si is the angular shift of the first hole under the carbide plate on the second knife relative to the first (base knife), as well as each first hole on the following knives relative to each first hole o from the previous knife, grad.; ; - the length of the side of the angle that limits the angular shift of the first hole under the carbide plate on the second "- 1 knife relative to the first (base knife), as well as each first hole on the following knives relative to each "3 first hole of the previous knife, mm. 2. A shaped cutter according to claim 1, which is characterized by the fact that the first plate of the base knife is located at the point where the profile line of the comb part meets the profile line of the inner face of the bandage. - - and? - and 1 («c) - 70 (42) ime) 60 b5