RU2287039C2 - Method of machining rail head surface - Google Patents

Abstract

FIELD: mechanical engineering.

SUBSTANCE: invention relates to methods of machining surfaces of rail head by cutting with rails in track using rail machining trains and under plant conditions on special metal cutting machine tools. Proposed method includes tools installed at different sections along and across rails with displacement relative to each other and shifting of tools and their rotation around axles with arrangement of axles in cross sections of rails so that working end face surfaces of tools perpendicular to rails are tangential to designed generatrix of rail running surface. Surface of rail head is machined by clockwise and/or counter-clockwise rotation tools with cutters. Main cutting edges of cutters are installed in working end face planes of tools which are shifted at relative speed along rail equal to at least one tenth of optimum cutting speed of rail material at condition that, for all tools, ratio of said speeds and also distance from axis of cutting tools to nearest limit of plane surface machined by tool is interpolated with due account of specific mathematical dependences. Tool is installed so that distance from its axis to farthest limit of plane surface machined by tool is mot less than 0.9 of its radius.

EFFECT: increased capacity at machining of rail with provision of its profile and quality of machined surface owing to use of high cutting speed with possibility of machining at one pass, reduced capital outlays and service expenses.

5 cl, 5 dwg

Description

The invention relates to methods for processing the surface of a rail head by cutting under conditions of a rail track using rail-processing trains and in factory conditions on special metal-working machines.

A known method of processing a rail on a special rail-milling machine model 6992M of OJSC Ulyanovsk Plant of Heavy and Unique Machines, in which the surface of the rail head is carried out by a profile cutter with a diameter of 560 mm with its axis of rotation parallel to the rail base and lying in the plane of its cross section at relative speed cutters along the rail (feed) 2.5-14 m / min and a maximum depth of cut layer 3 mm [Promotional brochure: Rail-milling machine. UZTS OJSC, Russia, Ulyanovsk, Gerasimova St., 10].

A similar method is known for treating the surface of a rail head under a rail track using a rail-processing train equipped with an SF03 rail-milling unit (Linsinger, Austria), in which the stock is taken out with several tools, profile cutters, with rotation axes parallel to the rail base and lying in the plane its cross section [Leaflet: Rail milling installation SF 03. LINSINGER, AUSTRIA].

The disadvantages of these methods of processing the surfaces of the rail head profile cutters is their low productivity - not more than 2500 m / h and the need to use a very expensive cutting tool - special profile cutters.

A known method of processing the surface of the rail head by grinding, adopted as the closest analogue [US Patent No. 4843765, MKI E 01 B 31/17, 1989], in which the processing is carried out by rotating grinding wheels. The method involves removing stock at the same time with several rotating tools, grinding wheels mounted in different sections along and across the rail with offset from each other, moving them along the rail and rotating around their axes with the axes in the transverse sections of the rail so that the working end planes perpendicular to them tools tangent to the calculated guide rail running surface, which, if the rail head is processed in several passes, is intermediate oh for the passage in question, and basic, if the passage of the tool is the last or only. This makes it possible to treat not only the rolling surface of the rail, but also to give the head a profile that corresponds to the average wear and tear required for optimal load distribution per rail. This method of grinding the surface of the rail head with rotating tools at a relative speed of their movement along the rail of 4-6 km / h provides removal in one pass of the maximum allowance of not more than 0.15 mm. Therefore, for removal from the rail head of an allowance with a thickness of 0.5 to 3 mm, 4 to 20 passes are required, while the actual productivity of processing the surface of the rail head at a relative speed of 6 km / h will significantly decrease to 1.5-0.3 km / h . Such a low actual productivity of this method requires a long time “window”, which causes a restriction or violation of the train schedule and, as a result, leads to high capital and operating costs. Another disadvantage of this processing method is the intensive wear of expensive grinding wheels, which is accompanied by a high dust content of the environment with an abrasive with metal chips, which is an environmental problem and leads, in particular, to the issue of sealing rooms and nodes of a rail grinding train.

The invention has the task to significantly increase the productivity of processing the rail head while ensuring its profile and the quality of the machined surface, in particular, by reducing the number of passes with increasing thickness of the allowance removed from the rail head.

In the invention, the surface of the rail head is treated with tools that are installed in different sections along and across the rail with offset from each other. Tools move along the rail and rotate around their axes. The axes are arranged in rail cross sections so that the working tool end faces perpendicular to them are tangent to the calculated guide of the rail running surface, which, if the rail head is machined in several passes, is intermediate for the passage under consideration, and basic if the tool passage is the last or only. The surface of the rail head is treated with tools of the right and (or) left rotation with cutters, the main cutting edges of which are installed in the working end planes of the tools. The processing is carried out by moving the tools with a relative speed along the rail, which is at least one tenth of the optimal cutting speed of the rail material.

,Namely,

,

where ν _s is the relative velocity of the tools along the rail;

[ν] is the optimal cutting speed of the rail material.

Moreover, for all processing tools, the ratio of these speeds m = ν _s / [ν] satisfies the following inequalities:

where q is the index of the processing tool (q = 1, ...);

- расстояние от оси q-го (q=1,...) инструмента до ближней (дальней) границы обработанной им плоской поверхности;

- the distance from the axis of the qth (q = 1, ...) tool to the near (far) boundary of the flat surface processed by it;

k=1, если обработка рельса попутная, и

k = 1 if the processing of the rail passing, and

, k=-1, если - встречная;

, k = -1 if - oncoming;

- ширина обработанной поверхности;

- width of the processed surface;

R _q is the radius of the tool.

а расстояние до ближней границы должно удовлетворять неравенствуThe processing tool is set so that the distance from its axis to the far boundary of the flat surface treated by it is not less than 0.9 of the tool radius

and the distance to the near border must satisfy the inequality

- линейная окружная скорость вершин главных режущих кромок обрабатывающих инструментов;Where

- linear peripheral speed of the vertices of the main cutting edges of the processing tools;

- конструктивный задний угол резцов инструмента;

- constructive rear corner of the tool cutters;

[α] = 3 ° ... 6 ° - the minimum allowable kinematic rear angle of the tool cutters.

In this case, the tops of the main cutting edges of the processing tools are provided with a linear peripheral speed, determined by the formula

and the corresponding tool angular velocity, determined by the formula

and feed to the cutter, determined by the formula

where z _q is the number of tool cutters.

Along with this, the processing tools are set so that the angle between the relative velocity vector of the tools along the rail and the linear peripheral velocity vector of any point of their main cutting edges located in the cutting zone is obtuse when passing along the rails and sharp when facing.

At the same time, the processing tools are set so that in some sections along and (or) across the rail, the tools simultaneously process the rail along the way, and on the other counter.

In addition, the processing of the rail can be carried out sequentially in several passes with one processing tool.

Thanks to the invention, a technical result is achieved, namely, the productivity of processing the rail head is substantially increased while ensuring its profile and the quality of the machined surface, in particular by reducing the number of passes in which an allowance of up to 3 mm is removed from the rail head in one pass, or in several (no more than five) passes.

инструментов вдоль рельса, траектории вершин главных режущих кромок q-го инструмента, векторы скоростей резания

и эпюры векторов линейных окружных скоростей

при попутной и встречной обработке, соответствующие виду Е на фиг.2; на фиг.5 - сечение - Г-Г на фиг.2. На фиг.1,..., 4 угловая скорость n_q q-го обрабатывающего инструмента, определяемая по формуле (6), обозначена

, если обработка рельса попутная, и

, если обработка встречная.Figure 1 shows the possible location of the q-th and (q + 1) -th processing tools along the rail and the surfaces P _q and P _{q + 1 of the} rail head treated by them; figure 2 is a section bB in figure 1; figure 3 and 4 is the vector of relative velocity

tools along the rail, the trajectories of the vertices of the main cutting edges of the qth tool, the cutting speed vectors

and diagrams of linear velocity vectors

when passing and oncoming processing, corresponding to type E in figure 2; figure 5 - section - GG in figure 2. In Fig. 1, ..., 4, the angular velocity n _{q of the} qth processing tool, determined by the formula (6), is indicated

if rail processing is incidental, and

if the processing is counter.

The proposed method of processing the surface of the rail head 1 involves removing stock at the same time with several tools 2. The processing tools are installed in different sections along and across the rail 1 with offset from each other (Fig. 1). Tools move along the rail and rotate around their axes O _q O _q . The axes are arranged in the rail cross sections so that the working end faces perpendicular to them T _q T _{q of the} tools are tangent to the calculated guide GLN of the rail running surface at points K (Fig. 2), which, if the rail head is machined in several passes, is intermediate for the considered passage, and basic, if the passage of the tool is the last or only.

при условии, что для всех обрабатывающих инструментов отношение этих скоростей

удовлетворяет неравенствам (1), (2) и (3).The essence of the proposed method lies in the fact that the processing tools 2, made, for example, in the form of cutters or cutter heads, right and (or) left rotation with cutters 3, the main cutting edges AB which are located in the working end planes T _q T _q tools ( figure 2), move with a relative speed ν _s along the rail, which is not less than one tenth of the optimal cutting speed [ν] of the rail material

provided that for all processing tools the ratio of these speeds

satisfies inequalities (1), (2) and (3).

. При этом расстояние H_1q от оси инструмента O_q до ближней границы P_1qP_1q должно удовлетворять неравенству (4).The processing tools are set so (FIGS. 3 and 4) that the distance H _2q from the tool axis O _q to the far boundary P _2q P _{2q of} the flat surface P _q treated by it is not greater than the radius R _{q of the} tool and not less than 0.9 of its radius

. In this case, the distance H _1q from the tool axis O _q to the near boundary P _1q P _1q must satisfy inequality (4).

, определяемую по формуле (5), и соответствующие ей угловую скорость

инструмента (формула (6)) и подачу на резец S_zq (формула (7)). При этом главные режущие кромки АВ резцов q-го инструмента входят в зону резания в точках С₁ и B₁ и выходят из зоны резания в точках С₂ и В₂ (фиг.3 и 4).The tops of the main cutting edges A of the processing tools are provided with a linear peripheral speed

determined by formula (5) and the corresponding angular velocity

tool (formula (6)) and feed to the cutter S _zq (formula (7)). In this case, the main cutting edges AB of the cutters of the qth tool enter the cutting zone at points C ₁ and B ₁ and exit the cutting zone at points C ₂ and B ₂ (FIGS. 3 and 4).

, обрабатывающих инструментов вдоль рельса и вектором линейной окружной скорости

любой точки М их главных режущих кромок АВ, находящейся в зоне резания C₁C₂B₂B₁ на расстоянии r_q от оси O_q инструмента, модуль которого равенWhen passing along the surface of the rail head, the angle β _q between the relative velocity vector

processing tools along the rail and linear peripheral velocity vector

of any point M of their main cutting edges AB located in the cutting zone C ₁ C ₂ B ₂ B ₁ at a distance r _q from the axis O _{q of the} tool, whose modulus is

It must be blunt, and with oncoming processing sharp. The sum of these vectors determines the cutting speed vector

и его направление. Увеличение скорости ν_s приводит к уменьшению угла γ_q между векторами

и

при попутной обработке с тупого угла до острого, а при встречной - с острого угла до 0° (фиг.3 и 4).The relative speed ν _{s of the} processing tools along the rail may be greater than the optimum cutting speed [ν] of the rail material. Moreover, their ratio m affects the modulus of the cutting speed vector

and its direction. An increase in the velocity ν _s leads to a decrease in the angle γ _q between the vectors

and

with passing processing from an obtuse angle to an acute angle, and with a counter-processing from an acute angle to 0 ° (Figs. 3 and 4).

, а следовательно, на изменение угла

. Тем самым в первом приближении векторы линейной окружной скорости

и скорости резания

считают равными.][For comparison, with traditional schemes of both passing and counter milling, the relative speed (feed) ν _{s of the} milling cutters along the workpiece is 100 ... 1000 times less than the linear _peripheral speed ν _0q . This means that an increase in the speed (feed) ν _s even several times practically does not affect the change in the module and the direction of the cutting speed vector

, and therefore, to change the angle

. Thus, in a first approximation, the linear peripheral velocity vectors

and cutting speeds

considered equal.]

The deviation of the cutting speed ν _q (M) at each point M of the main cutting edges AB located in the cutting zone from the optimum cutting speed [ν] of the rail material should not exceed ± 30%, i.e.

,

,

in this case, the largest deviations to a smaller and greater side from the optimal cutting speed [ν] of the rail material are equal, since

и

- наибольшая и наименьшая скорости резания ν_q, соответствующие точкам входа С₁ и выхода C₂ из зоны резания C₁C₂B₂B₁ главных режущих кромок АВ резцов инструментов (фиг.3 и 4).Where

and

- the largest and lowest cutting speeds ν _q corresponding to the points of entry C ₁ and exit C ₂ from the cutting zone C ₁ C ₂ B ₂ B _{1 of the} main cutting edges AB of the tool cutters (Figs. 3 and 4).

To reduce the longitudinal and transverse components of the vector of the resulting cutting force, equal to the sum of the cutting force vectors acting on all the cutting edges of the tools, each in its own cutting zone, set so that in some sections along and (or) across the rail, the tools simultaneously process rail, and on the other - oncoming.

In addition to simultaneously processing the surface of the rail head with several tools, it can be processed sequentially in several passes with one processing tool.

Thus, the proposed method allows for high-speed cutting conditions, depending on the properties of the rail material, the design of the processing tools and the tool material used in them, to significantly increase the processing speed of the rail head to 4000-8000 m / h while ensuring its profile and the quality of the processed surface.

Claims (5)

1. The method of processing the surface of the rail head, including installing in different sections along and across the rail with the offset of the processing tools relative to each other, moving them along the rail and rotating around their axes with the axes in the transverse sections of the rail so that the working end faces of the tools perpendicular to them tangent to the calculated guide rail running surface, characterized in that they process the surface of the rail head with tools of right and / or left rotation with cutters, heads which cutting edges are installed in the working end planes of tools that move with a relative speed along the rail, which is at least one tenth of the optimal cutting speed of the rail material, provided that for all processing tools the ratio of these speeds satisfies the following inequalities:

where m = ν _s / [ν]; ν _s is the relative speed of the tools along the rail; [ν] is the optimal cutting speed of the rail material; q is the index of the processing tool (q = 1, ...);

H _1q (H _2q ) is the distance from the axis of the qth (q = 1, ...) tool to the near (far) boundary of the flat surface treated by it; H _1q (H _2q ) is the distance from the axis of the qth (q = 1, ...) tool to the near (far) boundary of the flat surface treated by it; H _iq = H _1q , H _jq = H _2q , k = 1, if the processing of the rail passing, and H _iq = H _2q , H _jq = H _1q , k = -1 if oncoming; h _q = H _2q - H _1q - width of the treated surface; R _q is the radius of the tool; at the same time, the processing tool is set so that the distance from its axis to the far boundary of the flat surface processed by it is not less than 0.9 of its radius, and the distance to the near boundary must satisfy the inequality

where ν _0q is the linear _peripheral speed of the vertices of the main cutting edges of the processing tools; α _q - constructive rear corner of the tool cutters; [α] = 3 ... 6 ° - the minimum allowable kinematic rear angle of the tool cutters. 2. The method according to claim 1, characterized in that the tops of the main cutting edges of the processing tools provide a linear peripheral speed, determined by the formula

and the corresponding tool angular velocity, determined by the formula

and feed to the cutter, determined by the formula

where z _q is the number of tool cutters. 3. The method according to claim 2, characterized in that the processing tools are set so that the angle between the relative velocity vector of the tools along the rail and the linear peripheral velocity vector of any point of their main cutting edges located in the cutting zone is obtuse when passing along the rails and acute - in the oncoming one. 4. The method according to claim 3, characterized in that the processing tools are installed so that in some areas along and (or) across the rail, the tools simultaneously process the rail and on the other counter. 5. The method according to claim 3, characterized in that the processing of the rail is carried out sequentially for several passes with one processing tool.

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