RU105302U1 - SPRING TERMINAL FOR RAIL FASTENING - Google Patents

Abstract

 Spring clip rail fastening made of a rod of elastic material, bent to form a straight-line rail section, smoothly connected to two lateral extended sections, which are connected by arc napal sections with end sections, bent inside the terminal, characterized in that the cross section of the terminal bar along its entire length the length is made in the form of a central rectangle and two semicircles conjugated with it, with the major axis of symmetry of the section perpendicular to the plane of the terminal, height Rectangle ... is 0.45 0.55 of the width and the diameter of the semicircles is equal to the rectangle width.

Description

The utility model relates to the upper structure of a railway track, in particular, to a device for intermediate fastening of rails to reinforced concrete sleepers.

The known design of the spring terminal, which is made of bar material U-shaped in terms of shape. The terminal has a rectilinear section in contact with the rail shelf and rectilinear side sections that are connected by arc sections with end sections bent inward and to the shelf. The cross section of the terminal along its entire length is a circle (RF patent No. 2185471 "Rail fastening for the track on a reinforced concrete base", IPC 8 ЕВВ 9/48).

Also known is the design of the spring clip of the rail fastener, made of a round rod of elastic material and containing a straight rail part, passing along the radii of curvature to the side sections, beyond which are located the turns of the terminal, which end with bent end sections, and the end sections at a distance of at least 2 cm from their ends are made with kink (RF patent No. 2372436 "Anchor rail fastening, rail fastening anchor and rail fastening terminal", IPC 8 ЕВВ 9/30).

The above-mentioned constructions of spring terminals are made of a bar of circular cross section. Spring terminals during operation experience cyclically changing torsional and bending stresses. And when bending, the resulting stresses and strains depend on the moment of inertia about the neutral axis. If the moments of inertia with respect to the neutral axis for the circle and any other flat figures (square, rectangle, etc.) are equal, the area of the circle is always larger than the area of other figures. Therefore, the circular cross section of a rod experiencing bending is the most inefficient, since in order to provide the necessary strength, it is necessary to increase the diameter of the rod, which leads to an increase in the metal consumption of the product.

Closest to the technical nature of the proposed technical solution is the design of the spring terminal for rail rail fastening, which is made of a rod of elastic material of circular cross section with the formation of a B-shaped in the plane of the terminal. The terminal contains a straight rail section, the ends of which are smoothly connected to the extended lateral sections, and the arched nashpal sections located behind them are connected to the terminal sections bent into the terminal. At the same time, a part of each arched head section located closer to the end section is bent in a plane perpendicular to the terminal plane, and the bending curvature is commensurate with the radius of the terminal rod (RF patent No. 2252287 "Spring terminal for rail rail fastening", IPC 8 E01B 9/00, ЕВВ 9/48).

The known design of the spring terminal also has a high metal consumption, as it is made from a bar of a workpiece of circular cross section. During installation and operation, the spring terminal experiences bending and torsion strains. It is known that during bending, the resulting stresses and strains depend on the moment of inertia about the neutral axis. With the same bending moment and equal moments of inertia relative to the neutral axis for the circle and any other flat figures (square, rectangle, etc.), the area of the circle is always larger than the area of other figures. Therefore, the product formed by flexible from a bar with a cross section in the form of a circle has a high metal consumption. In addition, the implementation in a known design of the arc of the head sections with a bend in the planes perpendicular to the plane of the terminal, complicates the manufacturing process, as it requires the use of a special stamp.

The problem to which the claimed technical solution is directed is to reduce the metal consumption of the terminal while maintaining high operational properties.

The technical result provided by the proposed technical solution is to reduce the metal consumption of spring terminals for rail fastenings of the railway track.

According to the proposal, the well-known spring rail fastening terminal made of a rod of elastic material bent to form a rectilinear rail section smoothly connected to two lateral extended sections, which are connected by arc nashpal sections to the end sections bent inside the terminal, has a cross section of the terminal bar throughout the length is made in the form of a central rectangle and two semicircles conjugated to it, and the large axis of symmetry of the section is perpendicular to the plane of mm, while the height of the rectangle is (0.45 ... 0.55) its width, and the diameter of the semicircles is equal to the width of the rectangle.

The essence of the proposed technical solution is illustrated by drawings, where Fig. 1 shows a plan view of a spring terminal; figure 2 is a cross section along aa in figure 1.

The spring terminal of the rail fastening is made flexible from a spring steel rod of 40C2A or 60C2 grade. The terminal (Fig. 1) contains a straight-line rail section 1, the ends of which are smoothly connected to two lateral extended sections 2, and the arched nashpal sections 3 located behind them are connected to the end sections 4 bent into the terminal. In this case, the cross section of the terminal rod (Fig. 2) along its entire length is made in the form of a central rectangle 5 and two semicircles 6 conjugated to it, with the major axis of symmetry of the section perpendicular to the plane of the terminal. The height h of the rectangle is (0.45 ... 0.55) of its width b, and the diameter d of the semicircles 6 is equal to the width b of the rectangle 5.

The terminal block is installed on the reinforced concrete sleepers in such a way that the rail section 1 rests on the upper part of the rail shelf, the arc nashpal sections 3 come into contact with the bracket mounted on the rail, and a mortgage bolt is located between the end sections 4. A bracket is attached to the core of the embedded bolt, which interacts with the terminal sections 4 of the terminal. When tightening the nut on the embedded bolt, the rail section 1 presses the bottom of the rail against the railroad tie with a certain force. When the composition moves, the friction forces arising between the rail tie and the terminal keep the rail from longitudinal displacement. It should be noted that the friction forces substantially depend on the pressing forces of the rail sole to the railroad tie, which are created by clamping the terminal to the rail shelf during the fastening installation and must be maintained for a long time. The creation of the necessary pressing forces and the preservation of these forces during operation significantly affect the reliability of the railway and the costs of its maintenance.

A pilot batch of spring clamps of the ZhBR-65 type with a cross section in the form of a central rectangle and two semicircles conjugated with it was manufactured under the conditions of OJSC MMK-METIZ Magnitogorsk Hardware and Calibration Plant. The cross-sectional shape of the workpiece and the dimensions of the terminal were set in accordance with the proposed technical solution. The width of the rectangle b and the diameter d of the semicircles were set equal to 12 mm, and the height h of the rectangle varied in the range of 5.0 ... 7.0 mm. The terminals were made of calibrated steel grade 40С2А flexible in the cold state using a special bending stand. Given the dimensions of the cross section, the moment of inertia relative to the horizontal central axis is approximately equal to the moment of inertia for the circle ⌀ 17 mm, which is used in the construction of the ZhBR-65 terminal. The terminals were tested in accordance with the safety requirements for the operation of the railway track by triple compression by the load P = 25 kN applied along the axis of the bolt hole. The residual deformation should not exceed 1 mm. In addition, the stiffness of the terminals was determined. The test results are presented in the table.

Table

Test results for spring terminals ^* d, b, mm h mm The residual deformation after three times the load P = 25 kN Rigidity of the terminal, kN / mm 12.0 5,0 0.42 1.17 mm 0.75 5,4 0.45 0.93 mm 0.82 6.0 0.50 0.74 mm 0.92 6.6 0.55 0.63 mm 0.97 7.0 0.59 0.52 mm 1.16

Note: The average values are shown according to the test results of 10 terminals for each size.

Analysis of the test results showed that when the ratio of the height of the rectangle to the diameter of the semicircles less than 0.45, the residual deformation after three times crimping exceeds 1 mm, that is, the terminal does not meet the requirements of normative and technical documentation. At more than 0.55 terminals acquire high rigidity, which negatively affects their cyclic strength.

It should be noted that at the terminal of the developed design, the moment of inertia of the cross section relative to the neutral axis is approximately equal to the moment of inertia of the circle ⌀ 17 mm, which is used in the construction of the terminal ZhBR-65. This ensures equal strength of the ZhBR-65 terminal in accordance with the regulatory documentation for operation and the terminal of the proposed design. However, the cross-sectional area of the developed terminal is 18 ... 20% less than the cross-sectional area of the ZhBR-65 terminal. Thus, the use of terminals of the developed design provides a reduction in the metal consumption of products by 18 ... 20% while maintaining the regulated strength and elastic properties.

Claims (1)

Spring clip rail fastening made of a rod of elastic material, bent to form a straight-line rail section, smoothly connected to two lateral extended sections, which are connected by arc napal sections with end sections, bent inside the terminal, characterized in that the cross section of the terminal bar along its entire length the length is made in the form of a central rectangle and two semicircles conjugated with it, and the major axis of symmetry of the section is perpendicular to the terminal plane, height Rectangle ... is 0.45 0.55 of the width and the diameter of the semicircles is equal to the rectangle width.