RU2356770C1 - Bimetallic flanged brake shoe for locomotives and railmotor cars - Google Patents

Abstract

FIELD: railway transport industry.

SUBSTANCE: invention refers to railway transport industry, namely to braking mechanisms used at rolling railway equipment. Brake shoe includes steel plate, cast-iron arc-shaped body consisting of main and profile areas with made groove. The body is equipped with friction elements performed in a form of cylindrical inserts. From the back in the middle of the brake shoe body main area there is transverse lug with hole for V-shaped retaining key. At the back the main area of shoe arc-shaped body is equipped with mounting T-shaped lips at the edges for coupling with stop block and stiffeners in a form of triangular lugs. The depth of profile area lug exceeds the height of wheel tread flange by 0.85 of brake shoe main area thickness. Steel plate covers brake shoe back side, encloses transverse cast-iron lug and has holes in side surface at the level of lug holes for U-shaped retaining key. In the steel plate there are mounting holes for inserts fixing. Five metallic inserts are installed from the side of wearing surface perpendicular to groove outer side wall of profile area.

EFFECT: provision of brake shoe operation safety and effectiveness, elimination of thermodynamic cross cracks possible formation, increase of rolling equipment wheel life and provision of better heat extraction and cooling of brake shoe main and profile area working part.

10 cl, 10 dwg

Description

The invention relates to railway transport, in particular to brake equipment of traction rolling stock, and can also be used on other modes of transport in brake systems.

Existing metal and bimetallic brake pads of railway locomotive and motovoznogo rolling stock exhaust their frictional and tribological properties at speeds of rolling stock up to 140 km / h. In connection with the commissioning of new high-speed rail trains in the Russian Federation, the existing pads do not withstand the operating conditions, lose the friction coefficient and are destroyed in the molten iron.

Famous metal-ceramic blocks of foreign manufacture for high-speed mobile railway transport, in which, due to low viscosity and high fragility when interacting with the surfaces of the wheels, the friction mass breaks off steel substrates placed on the back of the blocks, cracks, punctures, delaminations appear, and, as a result, pads are destroyed, not having worked out 5% of their resource. Attempts to fasten the friction mass to the bearing plate with bolts, rivets, screws do not give positive results, the same damage occurs, the reliability and service life of the brakes are lost.

Considering the shortcomings of the known brake pads and the increased speeds of locomotive and motovo rail rolling stock up to 300 km / h and above, there is a need to create a new brake pad with high speed and, therefore, high heat resistant qualities that provide the permissible braking distance of locomotive and motovo rail rolling stock in compliance with safety standards on the federal railway transport NB ZhT TM 02-98.

Known brake pad by author. St. 1572889, B61H 1/00, publ. 06/23/90, containing a steel frame, a cast-iron arched body consisting of a main and profile sections with a stream made in it and equipped with inserts laid in rows in the block body from the side of the working friction surface, and the ridge inserts of the profile section are made in the form of cylindrical elements with a longitudinal cut-out and installed in the creek pads with the ability to cover and interact with the crest of the wheel brace.

However, in the known technical solution, the inserts are made of special cast iron having high hardness, and therefore cause intense wear on the surface of the wheels.

In addition, the implementation of the inserts of the main section prismatic, with a continuous surface of friction, reduces heat dissipation and contributes to even greater wear of friction pairs and reduce braking force due to a decrease in the coefficient of friction.

The closest is a brake pad containing a steel frame, a cast-iron arcuate body, consisting of the main and profile sections, with a stream made in it and equipped with inserts. The inserts are laid in rows in the block body from the side of the rubbing surface, and the ridge inserts of the profile section are made in the form of cylindrical elements with a longitudinal cut and installed in the stream of the block. All inserts are made of ductile metal. The inserts of the main part of the body of the block are cylindrical and placed in groups, the inserts have greater abrasiveness than the abrasiveness of the body of the block (Patent No. 2153994, IPC 7 B61H 1/00, F16D 65/04, 69/00, Bull. No. 22, 08/10/2000 )

A disadvantage of the known brake pads is the reduction of the braking effect at speeds of more than 140 km / h due to overheating of the inserts and lower friction coefficient. The shoe creates noise during operation.

In this block, as practice has shown, due to the cyclic interaction of the brace ridge with the profile section of the block equipped with ridge inserts, thermodynamic processes arise that contribute to the occurrence of transverse microcracks along the entire length of the ridge, which turn into transverse cracks in the brace of the wheel of the traction rolling stock.

The objective of the present invention is to provide a new design of the pads, providing reliable and effective braking during high-speed driving with an increase in the service life of the pads and wheels, as well as improving the manufacturing technology of brake pads with inserts.

The problem is achieved by the following set of features of the claimed invention.

The bimetallic ridge brake shoe for locomotives and motor vehicles contains a steel plate, a cast-iron arc-shaped body, consisting of the main and profile sections, with a stream made in it. The body is equipped with friction elements in the form of inserts of a cylindrical shape. The inserts of the main section of the block are laid in the body of the block from the side of the rubbing surface, where they are placed in two groups separated by a section without inserts R. The inserts of the profile section of the block are laid in the stream. The material of the inserts has a greater abrasiveness than the material of the body pads. The inserts are attached to the steel plate by welding. On the back side in the middle, the main part of the body of the block has a transverse tide with a hole for a wedge pin. The block is made by casting iron. On the back side, the main section of the arcuate body of the block is equipped at the edges with mounting stop tabs of a T-shape for pairing with the brake shoe and stiffeners in the form of triangular tides connecting the main and profile sections. The stream of the profile section has a depth exceeding the height of the ridge of the wheel bandage by 0.85 thickness of the main section of the block. The steel plate is made integral or prefabricated, consisting of two or three parts connected by welding. The steel plate covering the back side of the block goes to the outer side wall of the profile section and completely covers it. The steel plate covering the main part of the body of the block covers a transverse cast iron tide and has holes in the side surface at the level of the holes in the tide for the wedge pin. Mounting holes for fixing the inserts are made in the steel plate. Five metal inserts are installed on the side of the rubbing surface perpendicular to the outer side wall of the stream of the profile section.

A prefabricated metal plate can consist of two parts, one part covers the arched back surface of the main section of the block with a transverse tide and goes to the profile section of the block, covering its upper part, the other part covers the outer side wall of the profile section.

A prefabricated metal plate can consist of three parts: the first part covers the arched back surface of the main section of the block with a transverse tide, the second part covers the inner side wall of the profile section of the block, covering its upper part, the third part covers the outer side wall of the profile section.

The centers of the inserts of the profile section are placed sequentially along the arc of the base of the ridge of the wheel bandage or in a checkerboard pattern with a shift of 20 mm up and down relative to the arc of the base of the ridge of the wheel bandage, the centers of the inserts are equally spaced from each other along the arc of the base of the ridge of the wheel bandage, and the outermost inserts removed from the ends of the pads at 0.5 distance between the inserts.

The inserts are made of steel or metals and their alloys and are installed in the body of the main section of the block in the amount of 16-24 pieces.

The area of the plot P without inserts between groups of inserts is determined by the formula:

P = (0.17 ÷ 0.19) R,

where P is the area of the plot without inserts;

R is the total area of the working surface of the pads.

The diameter of the inserts of the profile section is equal to the diameter of the inserts of the main section and is:

D = L _k : (0.13 ÷ 0.17),

Where

L _k is the length of the block, mm;

D is the diameter of the inserts, mm

The length L _{1 of the} insert of the main section of the pads is:

L ₁ = (0.84 ÷ 0.86) · H ₁ ,

Where

H ₁ - pad thickness, mm.

The length L _{2 of the} cylindrical insert of the profile section of the block is:

L ₂ = (0.7 ÷ 0.72) · N ₂ ,

Where

H ₂ - the thickness of the side wall of the profile section, mm

The inserts are welded to the steel plate from the back through the mounting holes in pairs by a welding machine.

The novelty of the proposed design is as follows.

- On the back side, the main section of the arcuate body of the block is equipped at the edges with mounting stop tabs of a T-shape for pairing with the brake shoe and stiffeners in the form of triangular tides connecting the main and profile sections. Stiffeners allow you to strengthen the high profile area of the pads.

- The stream of the profile section has a depth exceeding the height of the ridge of the wheel bandage by 0.85 thickness of the main section of the block. The high profile part with a deep brook ensures that the profile section of the block does not contact the top of the wheel band crest almost until the block is completely worn out, which eliminates the occurrence of cyclic thermodynamic tension in the wheel band crest and, therefore, the occurrence of developing microcracks, prevents its destruction and increases its resource.

- The steel plate is made integral or prefabricated, consisting of two or three parts connected by welding.

- The steel plate covering the back side of the block goes to the outer side wall of the profile section and completely closes it. This allows you to significantly increase the strength of this section of the pads, ensuring the position of the pads relative to the wheel without slipping along the slope of the wheel brace, which is affected by significant braking forces.

- The steel plate covering the main part of the body of the block covers the transverse cast iron tide and has holes in the side surface at the level of the holes in the tide for the wedge pin. Thus, the tide is covered by a steel plate from the sides and from the top, which significantly increases the strength of this site. The reliability of the brakes is increased, since the tide is protected from snow and ice in the winter, which prevents its destruction.

- Mounting holes are made in the steel plate opposite the locations of the inserts. The inserts are welded to the steel plate from the back through the mounting holes in pairs by a welding machine. This allows you to accurately place the insert in the body of the pads, to avoid their displacement when casting iron, which significantly reduces the marriage in the manufacture and improves the quality of the pads.

- In the stream of the profile section, five metal inserts are installed in its outer side wall from the side of the rubbing surface, the axes of which are perpendicular to the outer side wall of the block stream, and the centers of the inserts are placed sequentially along the arc of the base of the wheel band crest or in a checkerboard pattern with a shift of 20 mm up and down relative to the arc of the base of the ridge of the wheel bandage at an equal distance from each other along this arc, and the extreme inserts are removed from the ends of the block by 0.5 distances between the inserts. The inserts on the side surface of the profile section are involved in counteracting the movement of the brake pads along the slope of the rolling surface of the wheel brace and provide balanced wear of the main and profile sections.

- A prefabricated metal plate can consist of two parts, one part covers the curved back surface of the main section of the block with a transverse tide and goes to the profile section of the block, covering its upper part, the other part covers the outer side wall of the profile section. The manufacture of a plate, consisting of individual parts connected by welding, simplifies the technology of its manufacture, without significant loss of quality.

- The prefabricated metal plate may consist of three parts: the first part covers the curved back surface of the main section of the block with a transverse tide; the second part covers the inner side wall of the profile section of the pads, covering its upper part; the third part covers the outer side wall of the profile section.

- The inserts are made of steel or metals and their alloys and are installed in the body of the main section of the block in the amount of 16-24 pieces.

- Formulas are given for determining: the area of the site without inserts P, the diameter of the cylindrical insert D, the length of the insert for the main section L ₁ and the length of the insert for the profile section L ₂ . Ranges of aspect ratio entered in the claims, as significant distinguishing features were established experimentally as a result of bench tests.

The design of the proposed block allows you to increase the reliability and efficiency by increasing the strength and reliability of the structure and technology of its production. Eliminates the possibility of transverse thermodynamic cracks at the top of the crest of the wheel brace with their subsequent development in the body of the wheel brace, which increases the resource of the wheels of the rolling stock.

Steel inserts in combination with a steel plate of a larger area than in the prototype provide better heat dissipation and cooling of the working part of the main and profile sections of the block.

The invention is illustrated by the drawings shown in Fig.1-10.

Figure 1 shows a view from the working side of the pads.

Figure 2 shows a view from the installation side of the block.

Figure 3 shows a cylindrical insert of the main section of the block.

Figure 4 shows a cylindrical insert of the side of the profile section of the pads.

Figure 5 shows a cross-section aa blocks with a solid metal plate.

Figure 6 shows a view of a steel plate consisting of three parts, with welds, with welded in pairs inserts, the working side.

Figure 7 shows a view of a steel plate consisting of three parts, with welds, with mounting holes for fixing the inserts and technological casting holes, the back side.

On Fig shows a cross section aa blocks with a prefabricated metal plate, consisting of two parts, with the location of the weld.

Figure 9 shows a view of a solid metal plate with welded in pairs inserts, the working side.

Figure 10 shows a steel plate, consisting of two parts, with a weld and holes, the back side.

The bimetallic ridge brake shoe for locomotives and motor vehicles consists of a main 1 and a profile 2 sections, made in the last stream 3. The main section 1 is equipped with friction elements in the form of inserts 4 of a cylindrical shape. The inserts 4 of the main section 1 of the block are laid in the body of the block from the side of the rubbing surface, where they are placed in two groups, separated by the section without inserts R. In the stream 3 of the profile section 2 of the block, inserts 5 are inserted. The inserts 4 and 5 are attached to the steel plate by welding. On the back side in the middle of the main section 1 of the block body there is a transverse tide 6 with an opening for the wedge pin 7. The block is made by casting iron into a mold. On the back side, the main section 1 of the arcuate body of the block is equipped at the edges with mounting stop tabs 8 of a T-shape for mating with the brake shoe and stiffening ribs 9 in the form of triangular tides connecting the main 1 and profile 2 sections located in the hollow recesses of the shoe.

The stream 3 of the profile section 2 has a depth exceeding the height of the ridge of the wheel bandage by 0.85 thickness H _{1 of the} main section 1 of the block. The steel plate 10 is made integral or prefabricated from parts connected by welding (Fig.6, 7, 9, 10). The steel plate 10, covering the back side of the pads, goes to the outer side wall of the profile section 2 and completely closes it (Fig. 8). The steel plate 10 is made of a solid steel sheet by stamping (Fig. 8, 9). The steel plate 10, covering the main section 1 of the body of the pads, covers the transverse tide 6 and has holes 11 in the side surface at the level of the holes 7 in the tide 6 under the wedge pin. In the steel plate 10, mounting holes 12 are made opposite the locations of the inserts 4 and 5. In the stream 3 of the profile section 2, five metal inserts 5 are installed in its outer side wall from the side of the rubbing surface, the axes of which are perpendicular to the outer side wall of the stream of the profile section 2, and the centers of the inserts 5 are placed sequentially along the arc of the base of the ridge of the wheel bandage (Figure 1) or in a checkerboard pattern with a shift of 20 mm up and down relative to the arc of the base of the ridge of the wheel bandage at an equal distance to each other from a friend along this arc. The extreme inserts 5 are removed from the ends of the pads by 0.5 distance between the inserts.

A prefabricated metal plate may consist of three parts: the first part 13 covers the curved back surface of the main section 1 of the block with a transverse tide 6. The second part 14 covers the inner side wall adjacent to the main section 1 of the block and covers the profile section 2 of the block from above. The third part 15 covers the outer side wall of the profile section 2. Parts 13 and 14 are connected using a weld seam A, and parts 14 and 15 are connected using a seam B (Fig.6,7).

Prefabricated metal plate may consist of two parts. One part 17 covers the arched back surface of the main section 1 of the block with a transverse tide 6 and goes to the profile section 2 of the block, closing it from above (Figure 10). The other part 15 covers the outer side wall of the profile section 2 of the pads. Parts 17 and 15 are connected by a weld seam B. The inserts 4 and 5 are welded by a seam C to a steel plate 10 or parts of a plate 13, 14, 15 or 15, 17 from the back through the mounting holes 12 in pairs by a welding machine. 6, 7, 8, 9, 10 show the technological holes 16 for casting iron.

Insert 4 of the main section 1 pads are placed in two groups, separated by a section without inserts R. The number of inserts 5 can vary from 16 to 24 pieces, depending on the required resource pads. Insertion of the inserts in the group is carried out in accordance with the coordinate grid developed on the computer, so as to ensure maximum overlap along the width of the rubbing surface of the shoe with inserts, which ensures a greater likelihood of picking up the scuff on the insert along the width of the shoe and the minimum wear of the shoe, as well as abrasion uniformity over the entire height pads over its entire surface, which affects the increase in the resource of the pads. Inserts in groups can be staggered or in rows. By changing the position of the rows, namely, the angle of rotation relative to the longitudinal axis of the pad of the inserts, it is possible to produce pads at various maximum braking speeds.

The inserts are made of plastic material - steel, which has a higher abrasiveness than the material of the block - cast iron. Also, inserts can be made of metals and their alloys. The proposed placement of the inserts ensures uniform contact of the pads with the wheel, preventing wear of the transition of the surface of the wheel to the ridge and eliminating the "undercut" of the ridge.

The proposed bimetallic block has a simple manufacturing technology. After pressing a steel plate or welding its constituent parts via the mounting holes 12 to plate welding machine with the rear side of the insert is welded in pairs, with the ends of the inserts 4 and 5 _^1/3 overlap area of the mounting hole 12. This enables accurately place the insert into the body pads avoiding their displacement when casting iron.

After welding, a package is formed, which includes a steel plate and all inserts. The package is installed in a mold and filled with molten iron, forming the body and a single working surface of the pads with a profile section and a protrusion for mounting the pads in the brake shoe. The part of the mounting holes not covered by the ends of the inserts contributes to a better distribution of cast iron during casting, which improves the quality of the casting.

The inserts are made from a bar on guillotine shears, and the formation of their package directly on a steel plate allows you to automate the entire process of manufacturing the pads, including filling the workpiece with molten cast iron, and releasing the pads from the mold, which generally sharply reduces the cost of the pads.

The length L ₁ insert the main section of the pads is determined by the formula:

L ₁ = (0.84 ÷ 0.86) · H ₁ ,

Where

H ₁ - pad thickness, mm.

The length L _{2 of the} cylindrical insert of the profile section of the block is determined by the formula:

L ₂ = (0.7 ÷ 0.72) · H ₂ ,

Where

H ₂ - the thickness of the side wall of the profile section, mm

The diameter of the inserts of the profile section is equal to the diameter of the inserts of the main section and is:

D = L _k : (0.13 ÷ 0.17),

Where

L _k is the length of the block, mm;

D is the diameter of the inserts, mm

To accelerate the running-in of the block according to the wheel configuration, all the inserts are filled with a layer of cast iron 3 ÷ 4 mm, which is laid in the calculation of the insert length, which ensures reliable braking immediately after changing the blocks. Then, after running in and starting to work together the inserts with the cast-iron body, more high-quality and effective braking with minimal wear of the block occurs, which ensures its high resource.

The mounting dimensions of the pads comply with GOST 1597-58 or TU - 32TsTVR - 453 - 78, and can also be made in accordance with any foreign standard.

The brake pads are operated by pressing the pads against the rolling surface of the rolling stock wheel.

During braking, when the brake shoe interacts with the tread surface of the wheel brace, elastoplastic friction occurs with a coefficient of 0.42 ÷ 0.1.

Elastoplastic friction conditions:

1. the body of the pads - cast iron, hardness 197 ÷ 255 NVS;

2. soft inserts - steel, hardness 150 НВС;

3. The rolling surface of the wheel brace - steel, hardness 235 NVS;

4. the maximum heat resistance of the pads is not lower than 950 ° C.

The proposed technical solution provides a significant increase in the reliability and efficiency of the brakes by increasing the strength and reliability of the design and production technology of the pads. Eliminates the possibility of transverse thermodynamic cracks at the top of the crest of the wheel brace with their subsequent development in the body of the wheel brace, which increases the resource of the wheels of the rolling stock. The side wall of the profile section of the block is reinforced with a steel plate.

Steel inserts in conjunction with a steel plate of a larger area than in the prototype, provide better heat dissipation and cooling of the working part of the main and profile sections of the block.

The location of the inserts in the stream in the side wall in a checkerboard pattern provides balanced wear of the side wall of the stream of the profile section and the working surface of the main section of the block.

Claims (10)

1. A bimetallic ridge brake shoe for locomotives and motovoz, containing a steel plate, a cast iron arc-shaped body, consisting of a main and a profile sections, with a stream made in it, the body is equipped with friction elements in the form of cylindrical inserts, the inserts of the main section of the block are embedded in the body of the block from the side of the rubbing surface, where they are placed in two groups, separated by section P without inserts, the inserts of the profile section of the block are laid in the stream, the material of the inserts has a large abrasiveness, than the material of the body of the pad, the inserts are attached to the steel plate by welding, from the back side in the middle the main section of the body of the pad has a transverse tide with a hole for the wedge pin, the pad is made by casting iron in a shape characterized in that on the back side of the main section of the arcuate body of the pad is equipped with the edges with installation stop tabs of a T-shape for interfacing with the brake shoe and stiffeners in the form of triangular tides connecting the main and profile sections, the stream of the profile section has a depth exceeding the height of the wheel band crest by 0.85 thickness of the main section of the block, the steel plate is made whole or prefabricated, consisting of two or three parts connected by welding, the steel plate covering the back side of the block goes to the outer side wall of the profile section and it is completely covered, the steel plate covering the main part of the body of the block covers the transverse cast iron tide and has holes in the side surface at the level of the holes in the tide for the wedge pin, in the steel mounting holes for fixing the inserts are made in the plate, five metal inserts are installed on the side of the rubbing surface perpendicular to the outer side wall of the stream of the profile section. 2. Bimetallic ridge brake shoe for locomotives and motocarriers according to claim 1, characterized in that the prefabricated metal plate consists of two parts, one part covers the curved back surface of the main section of the block with a transverse tide and goes to the profile section of the block, covering its upper part ; the other part covers the outer side wall of the profile section. 3. Bimetallic ridge brake shoe for locomotives and motor vehicles according to claim 1, characterized in that the prefabricated metal plate consists of three parts: the first part covers the curved back surface of the main section of the block with a transverse tide; the second part covers the inner side wall of the profile section of the pads, covering its upper part; the third part covers the outer side wall of the profile section. 4. The bimetallic ridge brake shoe for locomotives and motor vehicles according to claim 1, characterized in that the center of the insert section of the profile section are placed sequentially along the arc of the base of the ridge of the wheel bandage or in a staggered manner with a shift of 20 mm up and down relative to the arc of the base of the ridge of the wheel bandage, the centers of the inserts are equally spaced from each other along the arc of the base of the ridge of the wheel bandage, and the extreme inserts are removed from the ends of the block by 0.5 distances between the inserts. 5. Bimetallic ridge brake shoe for locomotives and motor vehicles according to claim 1, characterized in that the inserts are made of steel or metals and their alloys and are installed in the body of the main section of the shoe in the amount of 16-24 pieces. 6. Bimetallic ridge brake shoe for locomotives and motovozov according to claim 1, characterized in that the area of the plot P without inserts between groups of inserts is determined by the formula:
P = (0.17 ÷ 0.19) R,
where P is the area of the plot without inserts;
R is the total area of the working surface of the pads. 7. The bimetallic ridge brake shoe for locomotives and motor vehicles according to claim 1, characterized in that the diameter of the inserts of the profile section is equal to the diameter of the inserts of the main section and is:
D = L _k : (0.13 ÷ 0.17),
where L _k is the length of the block, mm;
D is the diameter of the inserts, mm 8. The bimetallic ridge brake shoe for locomotives and motor vehicles according to claim 1, characterized in that the length L _{1 of the} insert of the main section of the shoe is:
L ₁ = (0.84 ÷ 0.86) × H ₁ ,
where H ₁ - the thickness of the pads, mm 9. The bimetallic ridge brake shoe for locomotives and motor vehicles according to claim 1, characterized in that the length L _{2 of the} cylindrical insert of the profile section of the shoe is:
L ₂ = (0.7 ÷ 0.72) × H ₂ ,
where H ₂ is the thickness of the side wall of the profile section, mm 10. Bimetallic ridge brake pad for locomotives and motocarriers according to claim 1, characterized in that the inserts are welded to the steel plate from the back through the mounting holes in pairs by a welding machine.

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