CN117272587A

CN117272587A - Design method of contact structure of fixed frog and wheel rail and rail transit structure

Info

Publication number: CN117272587A
Application number: CN202311023074.2A
Authority: CN
Inventors: 张海华; 唐丽; 谭元键; 耿云源
Original assignee: China Railway Construction Heavy Industry Group Co Ltd
Current assignee: China Railway Construction Heavy Industry Group Co Ltd
Priority date: 2023-08-15
Filing date: 2023-08-15
Publication date: 2023-12-22

Abstract

The invention discloses a design method of a contact structure of a fixed frog and a wheel rail and a rail transit structure, which comprises the following steps: s1, analyzing the bearing width of the wheel-rail contact according to the static geometrical relationship of the wheel-rail contact; s2, setting a wheel rail contact form according to the bearing width of the wheel rail contact; s3, designing a frog structure according to the set wheel-rail contact mode. The design method provides a concept of minimum allowable bearing width, gives a depth theoretical support for the design of the fixed frog wheel structure, effectively guides the structural design of the fixed frog structure, obtains the fixed frog structure which meets the requirements of practical application environments, reduces the influence of 'harmful space' on rail traffic, and effectively improves the overall stability and safety of the rail traffic structure.

Description

Design method of contact structure of fixed frog and wheel rail and rail transit structure

Technical Field

The invention relates to the field of rail transit turnouts, in particular to a design method of a contact structure of a fixed frog and a wheel rail and a rail transit structure.

Background

Railway switches are key devices for rolling stock to enter or cross another line from one line to achieve rolling stock steering or crossing, wherein fixed frog is one of the core components of railway switches.

By virtue of the advantages of simple structure, good integrity, stable performance and the like, the fixed frog of the railway turnout has the duty ratio of 90 percent, and the fixed frog structure is shown in figure 1. The fixed frog is divided into a wing rail and a frog center according to the driving position. In order for the wheel rim to pass normally, a certain width, namely the width of the rim groove, must be maintained between the wing rail and the working edge of the fork core. The minimum distance between the wing rails, the frog throat, from the throat to the actual tip of the frog center, is a range of gauge line discontinuities, which range is referred to as "hazardous space". The "hazardous space" of the fixed frog is not eliminated, and is an inherent property of the fixed frog.

When the wheel runs from the wing rail to the fork center and passes through the harmful space of the frog, the original running direction can be offset due to the loss of the guiding of the track line, as shown in fig. 2, the wheel rim can strike the tip of the fork center when the wheel is light, as shown in fig. 3, the wheel rim can enter the heterolateral wheel rim groove when the wheel rim is heavy, and the derailment accident occurs.

When the wheel rolls to the rail from the wing rail through the frog, the wheel gradually leaves the wing rail, and the tread of the wheel is a cone, so that the wheel descends. Referring to fig. 4 to 7, after the wheel rolls on the rail, the wheel gradually returns to the original horizontal plane. The reverse operation is also the same. Therefore, when the wheel set passes through the harmful space of the frog, a vertical falling trend always exists, so that the driving smoothness is affected. When severe, the tip of the frog core is impacted from above, so that the frog core with a small section of the frog is damaged, and the driving safety is affected when severe. As shown in fig. 8 to 10, when the wheel passes through the "harmful space", the contact point between the wheel and the wing rail moves outwards gradually, and the wheel descends slowly due to the conical shape of the tread surface of the wheel. The center motion track of the wheel can sink in the harmful space, and the running smoothness and the frog service life can be influenced. And the sinking amplitude can be increased along with the increase of the frog angle, and the generated hazard can be gradually increased.

Aiming at the problems, in order to improve the driving smoothness and prolong the service life of the frog, a common method is to raise the height of the wing rail from the throat backwards. When the frog angle is less than 45 °, referring to fig. 11, the wheel always contacts the wing rail or the fork core without falling into the rim groove when passing through the "hazardous space", and the normal tread bearing fork passing mode can be adopted. However, as the angle of the frog increases, the wing rail that it is required to raise increases, and when there is an angle greater than 45 °, referring to fig. 12, the wheel passes through the "hazardous space" with the point of contact of the wheel rail moving outward to the wheel tread, but not yet in contact with the fork core. The wheel falls into the rim groove and then is punched with the fork center, and the strong impact can be generated in the way of passing through the wheel, so that the frog is damaged. In this case, the rim is usually used for carrying the fork, namely, the shallow groove design of the frog rim groove is adopted. The principle of the wheel rim crossing is that the bottom of the wheel rim groove is lifted in the range of harmful space, so that the wheel rim bears the weight of the vehicle, the center movement of the wheel in the process keeps horizontal, and the vehicle runs smoothly.

In summary, regarding what crossing mode is adopted in what situation, the current method is to distinguish by the frog angle, and according to domestic experience and recommended in the switch design manual, the 45 ° frog angle becomes the critical angle of the contact mode of the frog wheel rail, and only the limit angle of the frog is adopted to determine that the contact crossing mode of the frog wheel rail is adopted, but because the wheel tread and the rail type are various, the relationship of the wheel rail is extremely complex, the depth of the rim groove of the frog designed by the existing method lacks the theoretical support of depth, the structural design such as the depth of the rim groove of the frog cannot be effectively guided, and the final landing structure always needs to be modified and adjusted.

Disclosure of Invention

The invention provides a design method of a contact structure of a fixed frog and a wheel rail and a rail transit structure, and aims to solve the technical problem that the conventional design method cannot meet the use requirement when the structural design is carried out by taking the frog angle as a critical angle.

The technical scheme adopted by the invention is as follows:

a design method of a contact structure of a fixed frog and a wheel rail comprises the following steps:

s1, analyzing the bearing width of the wheel-rail contact according to the static geometrical relationship of the wheel-rail contact;

s2, setting a wheel rail contact form according to the bearing width of the wheel rail contact;

s3, designing a frog structure according to the set wheel-rail contact mode.

As a further improvement of the above technical solution, when calculating the bearing width of the wheel-rail contact according to the static geometrical relationship of the wheel-rail contact, step S1 includes:

and analyzing the contact static geometrical relationship of the wheel rail according to the width of the wheel rim, the back distance of the transverse rim, the maximum rim groove width of the straight frog strands, the maximum rim groove width of the bent frog strands, the minimum allowable section width of the center rail, the minimum allowable tread width of the wing rail and the fixed frog angle by taking the track gauge line as a reference plane.

As a further improvement of the technical proposal, when the bearing width of the wheel-rail contact is calculated according to the static geometrical relationship of the wheel-rail contact, the bearing width of the wheel-rail contact is analyzed according to the static geometrical relationship,

wherein A is the width of the wheel rim, B is the back distance of the transverse rim, C is the maximum rim groove width of the straight frog strands, D is the maximum rim groove width of the bent frog strands, E is the minimum allowable section width of the head rail, F is the minimum allowable tread width of the wing rail, beta is the fixed frog angle, and the limit value is 0 or positive number.

As a further improvement of the above technical solution, step S2 includes:

if the calculated value is more than or equal to the limit value, adopting a tread bearing bifurcation mode,

if the calculated value of the formula is less than the limit value, adopting a rim bearing type wheel rail contact mode.

As a further improvement of the above technical solution, step S3 includes:

if the tread bearing fork passing mode is adopted, the rim groove is designed into a deep groove structure,

if the wheel-rim bearing type wheel-rail contact mode is adopted, the wheel-rim groove is designed to be of a shallow groove structure.

As a further improvement of the technical scheme, if the rim groove is designed into a deep groove structure, the height of the wing rail is gradually raised to the standard height from the throat position of the frog to the actual tip position of the frog center.

As a further improvement of the technical scheme, if the rim groove is designed to be of a shallow groove structure, the bottom of the rim groove from the throat position of the frog to the actual tip position of the frog center is lifted to a preset depth.

As a further improvement of the above technical solution, the design method further includes: and arranging guard rails on the opposite rails of the frog positions to restrain the wheels.

As a further improvement of the above technical solution, the rim width of the wheel does not include a rim end chamfer, and the lateral rim back distance is a lateral rim back distance when rim back wear is maximum.

According to another aspect of the invention, a rail transit structure is provided, and the design method of the contact structure of the fixed frog and the wheel rail is applied.

The invention has the following beneficial effects:

the design method is characterized in that the minimum allowable bearing width of the fixed frog and the contact of the wheel rail is analyzed based on the static geometrical relationship of the contact of the wheel rail, the contact form of the wheel rail is set according to the contact bearing width of the wheel rail, namely, when the wheel passes through the harmful space of the frog in the normal tread bearing form, the minimum allowable bearing width of the contact of the wheel rail is ensured under the worst condition, if the contact cannot be ensured, other contact forms are adopted, and then the structural design of the frog is carried out according to the selected contact form; compared with the critical angle selected by taking a 45-degree angle as a contact mode of a frog wheel rail in the guidance of a turnout design manual in the prior art, the design method provides a minimum allowed bearing width concept, gives a depth theoretical support for the design of a fixed frog wheel structure, effectively guides the structural design of the fixed frog structure, obtains the fixed frog structure which meets the requirements of practical application environment, reduces the influence of 'harmful space' on rail traffic, and effectively improves the overall stability and safety of the rail traffic structure.

In addition to the objects, features and advantages described above, the present invention has other objects, features and advantages. The invention will be described in further detail with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention. In the drawings:

FIG. 1 is a schematic view of a prior art fixed frog construction;

FIG. 2 is a schematic view of a prior art wheel rim strike fork tip;

FIG. 3 is a schematic illustration of a prior art wheel misentering a heterolateral rim channel;

FIG. 4 is a schematic prior art, unaided frog travel to throat;

FIG. 5 is a schematic view of an unaided prior art frog entering "hazardous space" and an impending contact frog core;

FIG. 6 is a schematic view of a prior art unaided frog transitioning from a wing rail to a frog center;

FIG. 7 is a schematic view of a prior art unaided frog traveling to the frog center;

FIG. 8 is a schematic illustration of an ideal wheel crossing in the prior art;

FIG. 9 is a prior art wheel no-measure actual bypass schematic;

FIG. 10 is a schematic illustration of a center motion trajectory of a prior art wheel through a hazardous space;

FIG. 11 is a schematic illustration of a prior art frog having no means for passing the frog when the frog angle is less than 45;

FIG. 12 is a schematic illustration of an unarmed fork crossing with a frog angle greater than 45 degrees in the prior art;

FIG. 13 is a diagram of static wheeltrack geometry of a preferred embodiment of the present invention;

FIG. 14 is a schematic view of the tread of the preferred embodiment of the present invention with the frog traveling to the throat in a fork-carrying manner;

FIG. 15 is a schematic view of a preferred embodiment of the present invention showing the frog entering "hazardous space" and approaching contact frog center in the fork-carrying tread pattern;

FIG. 16 is a schematic view of a frog transitioning from a wing rail to a fork core in a tread load fork-passing manner in accordance with a preferred embodiment of the present invention;

FIG. 17 is a schematic view of a preferred embodiment of the present invention with the tread surface carrying the fork traveling to the center of the fork;

fig. 18 is a schematic view of the protection of the guard rail against "hazardous spaces" in accordance with the preferred embodiment of the present invention.

Detailed Description

It should be noted that, in the case of no conflict, the embodiments and features in the embodiments may be combined with each other. The invention will be described in detail below with reference to the drawings in connection with embodiments.

Referring to fig. 13 to 18, a preferred embodiment of the present invention provides a method for designing a contact structure of a fixed frog and a wheel rail, comprising the following steps:

s3, designing a frog structure according to the set wheel-rail contact mode.

It can be understood that the design method analyzes the minimum allowable bearing width of the fixed frog and the contact of the wheel rail based on the static geometrical relationship of the contact of the wheel rail, and sets the contact form of the wheel rail according to the contact bearing width of the wheel rail, namely, when the wheel passes through the harmful space of the frog in the normal tread bearing form, the minimum allowable bearing width of the contact of the wheel rail is ensured under the worst condition, if the minimum allowable bearing width of the contact of the wheel rail cannot be ensured, other contact forms are adopted, and then the structural design of the frog is carried out according to the selected contact form; compared with the critical angle selected by taking a 45-degree angle as a contact mode of a frog wheel rail in the guidance of a turnout design manual in the prior art, the design method provides a minimum allowed bearing width concept, gives a depth theoretical support for the design of a fixed frog wheel structure, effectively guides the structural design of the fixed frog structure, obtains the fixed frog structure which meets the requirements of practical application environment, reduces the influence of 'harmful space' on rail traffic, and effectively improves the overall stability and safety of the rail traffic structure.

Further, when calculating the bearing width of the wheel-rail contact according to the static geometrical relationship of the wheel-rail contact, step S1 includes:

analyzing a wheel-rail contact static geometrical relationship according to the width of a wheel rim, the back distance of a transverse rim, the maximum rim groove width of a straight frog, the maximum rim groove width of a curved frog, the minimum allowable section width of a center rail, the minimum allowable tread width of a wing rail and the angle of a fixed frog by taking the track gauge line as a reference plane, analyzing the wheel-rail contact static geometrical relationship according to the parameters by taking the track gauge line as the reference plane, and judging whether the bearing width of the wheel-rail contact meets the use requirement in the practical application environment based on the analysis method;

in the embodiment, when the bearing width of the wheel-rail contact is calculated according to the static geometrical relationship of the wheel-rail contact, the bearing width of the wheel-rail contact is analyzed according to the method 1,

wherein A is the width of a wheel rim, B is the back distance of a transverse rim, C is the maximum rim groove width of a straight frog, D is the maximum rim groove width of a bent frog, E is the minimum allowable section width of a head rail, F is the minimum allowable tread width of a wing rail, beta is the angle of a fixed frog, and the limit value is 0 or positive number;

it should be understood that the calculation method can intuitively reflect the contact static relationship of the frog wheel and rail, has simple calculation process and can be applicable to different types of wheel treads and switch frog types; the calculated value obtained in the calculation mode is the difference between the actual contact width of the tread of the wheel and the minimum allowable bearing width, and the difference (calculated value) is ensured to be larger than the limit value, namely the bearing width of the tread contact meets the requirement, therefore, the limit value must be 0 or a positive number, and it is required to be noted that the limit value is usually taken as 0, namely the minimum allowable bearing width is satisfied, and the limit value can be properly increased under the condition of considering other interference factors such as material characteristics, environmental influence and the like;

the wheel rim width does not comprise a rim end face chamfer, the transverse rim back distance is the transverse rim back distance when the rim back abrasion is maximum, the minimum allowable section width of the center rail can bear the minimum allowable section width of the wheel rolling, the minimum allowable tread width of the wing rail can bear the minimum allowable tread width of the wheel rolling, and therefore the bearing capacity of the bearing width under the most adverse condition is fully considered, the minimum allowable bearing width is obtained, and the design safety and rationality are ensured;

further, step S2 further includes:

if the calculated value of the formula 1 is more than or equal to the limit value, a tread bearing and crossing mode is adopted, namely the bearing width of the wheel rail contact meets the requirement, and the running safety can be ensured by adopting a conventional tread bearing and crossing mode;

if the calculated value of the formula 1 is smaller than the limit value, adopting a wheel rim bearing type wheel rail contact mode, namely, the bearing width of the wheel rail contact cannot meet the requirement at the moment, and ensuring the driving safety of the wheels through the frog by adopting a wheel rim bearing mode;

based on this, step S3 includes:

if a tread bearing fork passing mode is adopted, the rim groove is designed into a deep groove structure;

specifically, if the rim groove is designed to be a deep groove structure, the height of the wing rail is gradually raised to the standard height from the throat position of the frog to the actual tip position of the frog center, and referring to fig. 14 to 17, the wing rail height is gradually raised in the 'harmful space' range, so that the wheel center track is still unchanged, after the small section of the frog center is avoided, the height is slowly lowered to the normal height, so that the wheel contact point is transited back to the frog center, the service life of the frog is effectively prolonged, and the driving smoothness is improved; the specific size of the deep groove structure is designed according to the actual wheel rail and frog structure parameters by referring to the existing structure design method;

if the wheel-rim bearing wheel-rail contact mode is adopted, the wheel-rim groove is designed to be a shallow groove structure;

specifically, if the rim groove is designed to be a shallow groove structure, the bottom of the rim groove from the throat position of the frog to the actual tip position of the frog center is raised to a preset depth, and referring to fig. 12, the bottom of the rim groove is raised in the 'harmful space' range so as to enable the wheel rim to bear weight, so that the movement of the wheel center is kept horizontal, and the running is smooth; the specific size of the shallow slot structure is designed according to the actual wheel rail and frog structure parameters by referring to the existing structure design method;

in some embodiments, the design method further comprises: providing a guard rail to constrain the wheel in the opposing track of the frog position, referring to fig. 18, the guard rail structure can guide the wheel to travel, avoiding derailment or loading the frog center tip; in this embodiment, the design method can ensure driving safety, and the guard rail can be omitted in the specific implementation process, so that cost is effectively reduced.

On the other hand, the embodiment also provides a rail transit structure, and the design method of the contact structure of the fixed frog and the wheel rail is applied.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The design method of the contact structure of the fixed frog and the wheel rail is characterized by comprising the following steps:

s3, designing a frog structure according to the set wheel-rail contact mode.

2. The method of claim 1, wherein the step of calculating the bearing width of the wheel-rail contact according to the static geometrical relationship of the wheel-rail contact comprises the steps of

S1 comprises the following steps:

3. The method for designing a contact structure between a fixed frog and a wheel rail according to claim 2, wherein when calculating a bearing width of the wheel rail contact according to a static geometrical relationship of the wheel rail contact, analyzing the bearing width of the wheel rail contact according to formula (1),

4. The method of designing a contact structure between a fixed frog and a wheel rail as claimed in claim 3, wherein the step S2 includes:

if the calculated value of the formula (1) is more than or equal to the limit value, adopting a tread bearing bifurcation mode,

if the calculated value of the formula (1) is less than the limit value, adopting a rim bearing type wheel rail contact mode.

5. The method of claim 4, wherein the step S3 includes:

6. The method of claim 5, wherein if the rim groove is designed as a deep groove structure, the height of the wing rail is gradually raised from the throat position of the frog to the actual tip position of the frog center to the standard height.

7. The method of claim 5, wherein if the rim groove is designed as a shallow groove structure, raising the bottom of the rim groove from the throat position of the frog to the actual tip position of the frog core to a predetermined depth.

8. The method of designing a fixed frog and wheel rail contact structure according to any one of claims 1-7, further comprising: and arranging guard rails on the opposite rails of the frog positions to restrain the wheels.

9. The method of claim 2-7, wherein the wheel rim width does not include a rim end chamfer, and the lateral rim back is the lateral rim back at which rim back wear is greatest.

10. A rail transit structure, characterized in that the method for designing the contact structure of the fixed frog and the wheel rail according to any one of claims 1 to 9 is applied.