Device for monitoring position of movable element of turnout

Abstract

FIELD: railway equipment.SUBSTANCE: device for monitoring the position of a movable element of a turnout comprises a housing in which a shaft and a switch unit are secured, consisting of at least two switches, one of which monitors the pressed state of the movable element of the turnout, and the second monitors the retracted state of the movable element of the turnout. A yoke is secured to the shaft, which has two working parts, each of which has a recess. The profile of the recess in the cross-section of the yoke has a triangular shape, ensuring the opening of the contacts of the corresponding switch when its interacting element enters the specified recess during rotation of the shaft.EFFECT: increasing the accuracy of the device for monitoring the position of the movable element of the turnout by reducing the influence of mechanical hysteresis on the contacts of the switches.8 cl, 3 dwg

Description

[0001] Field of invention

[0002] The invention relates to control devices and is intended to obtain information about the position of the moving parts of a switch relative to the fixed ones and can be used in the railway industry.

[0003] Background of the invention

[0004] Reliable and accurate control of extreme positions of movable elements of turnouts is one of the key tasks in ensuring the safety of train traffic.

[0005] A device for monitoring the position of a movable element of a turnout [CN101580072A, publication date: 11 / 18 / 2009] was selected as a prototype. The device comprises a housing in which a shaft and a switch block are fixed, one of which monitors the pressed state of the movable element of the turnout, and the second monitors the retracted state of the movable element of the turnout. A drive element is fixed on the shaft, designed to interact with the switches, made in the form of two separate, structurally speaking, units - a fixed group and an adjustable group. Each of these groups has a trapezoidal recess, when the roller associated with the corresponding switch enters it, its contacts open. In this case, the adjustable starting group is equipped with a mechanism for adjusting its angular position on the shaft, including a pinion, a handle and internal / external gear engagements.

[0006] Despite solving the position control problem, analysis of the design and operating principle of the prototype reveals a number of significant shortcomings that prevent the achievement of a high level of accuracy, reliability and ease of operation, which directly affects safety.

[0007] The main drawback that determines the device's low accuracy is the kinematically inefficient profile of the roller recess, which has a trapezoidal cross-section. The trapezoid's flat base creates a so-called dead zone—a range of movement within which the device is insensitive to changes in the position of the controlled element, making it impossible to detect minimal but significant displacements. To ensure unambiguous and precise operation, the prototype design includes an additional compensating unit in the form of a spring-loaded pusher located at the entrance to the recess. It should be noted that this design does not eliminate hysteresis, but remains a source of failure. This pusher is a precision mechanism comprising a spring and friction surfaces and is extremely vulnerable to external factors, including contamination, moisture, icing, and thermal deformation.Its jamming or degradation of the spring's elastic properties leads to failure, in which the instantaneous action described in the prototype is eliminated. However, the device continues to function, transmitting unreliable data about the pointer's position to the control system. Moreover, this design has extremely low repairability, as failure of this element requires replacement of the entire assembly.

[0008] Also noteworthy are the design flaws of the drive element itself, which contains the aforementioned recess. It is responsible for actuating the switches and is constructed as two structurally independent assemblies—a fixed group and an adjustable group. The adjustable group is a complex mechanism, including gears, a handle, and toothed engagements. This design solution reduces overall reliability and fault tolerance due to the numerous mating components subject to wear, vibration, and adverse external factors typical of railway operation. Furthermore, the adjustment process requires maintenance personnel to perform a multi-step sequence of operations, which not only increases the labor intensity of maintenance but also creates a predisposition to error.Incomplete or incorrect fixation of the adjustable group may lead to spontaneous displacement of the control point under the influence of vibration loads, which may lead to a loss of accuracy and creates a direct threat to traffic safety.

[0009] Thus, the technical problem is the need to create a control device that would ensure high accuracy and reliability due to the kinematic elimination of hysteresis, and at the same time would have the simplest, most reliable and fault-tolerant design.

[0010] Disclosure of the essence of the invention

[0011] The technical result that the invention is aimed at achieving consists in increasing the accuracy of the device for monitoring the position of the movable element of the switch by reducing the influence of mechanical hysteresis on the contacts of the switches.

[0012] An additional technical result, which the invention is aimed at achieving, consists in increasing the smoothness of the entry of the interacting element into the recess and reducing the wear of the edge of the recess.

[0013] An additional technical result, which the invention is aimed at achieving, consists in increasing the reliability of fixation of the interacting element.

[0014] An additional technical result, which the invention is aimed at achieving, is to reduce the risk of false alarms of the control device and to increase the reliability of control.

[0015] The essence of the invention is as follows.

[0016] A device for monitoring the position of a movable element of a turnout comprises a housing in which a shaft and a switch assembly are secured. The switch assembly consists of at least two switches, one of which monitors the pressed state of the movable element of the turnout, and the second of which monitors the retracted state of the movable element of the turnout. Unlike the prototype, a yoke is secured to the shaft, having two working parts, each of which has a recess. The recess profile in the cross-section of the yoke has a triangular shape, ensuring the opening of the contacts of the corresponding switch when its interacting element enters said recess during rotation of the shaft.

[0017] A device for monitoring the position of a movable turnout element is designed to obtain information about the position of the movable turnout elements relative to the fixed ones. The movable turnout element, the position of which is monitored by the device in accordance with the present invention, may be a switch point, monitored relative to a fixed stock rail, or a frog core, monitored relative to fixed guardrails.

[0018] The housing supports the components of the switch position monitoring device. For this purpose, the housing can be designed as a base with a container, a container with a lid, two mating containers, or a base, walls, and a lid. The housing can be made of any structural material, including metal, polymer, or composite materials. The housing can be provided with holes, grooves, or mounting pads for securing the components of the switch position monitoring device using connecting elements.

[0019] The housing contains a shaft and two switches. The shaft supports a crank mechanism and a yoke. Specifically, the yoke can be attached to the portion of the shaft located inside the housing, while the crank mechanism can be attached to the portion of the shaft located outside the housing.

[0020] The crank-rocker mechanism ensures the conversion of the linear movement of the movable element of the turnout into an uneven rotational movement of the shaft of the yoke fixed to it, for which purpose the link of the crank-rocker mechanism is fixed to the movable element of the turnout.The degree of unevenness of the rotational movement of the shaft and the yoke fixed thereto can be adjusted by changing the working length of the link, for which purpose the crank-link mechanism can have an adjustment block, which is fixed on the link with the possibility of linear movement along it and to which the crank can be pivotally connected, and the adjustment of the working length of the link can be ensured by moving the adjustment block relative to the link and fixing it in a given position, which provides the possibility of more precise adjustment of the device and its adaptation to turnouts with different stroke lengths of the movable element, due to which high accuracy of control of the position of the movable element of the turnout is ensured.

[0021] The switches monitor the state of the movable element of the turnout. In particular, one of them monitors the pressed state of the movable element, and the other the retracted state of the movable element. Each switch can be configured as normally closed or normally open and can be represented by a single normally closed or open electrical contact or a single normally closed or open limit switch. However, in the most preferred embodiment, each switch can be represented by a pair of normally closed or open electrical contacts, which increases the accuracy of determining the state of the movable element of the turnout. The switches can be located on a single circle, the center of which coincides with the longitudinal axis of the shaft. The switches can be fixed in the device housing relative to the shaft.

[0022] To further enhance reliability and reduce the risk of false alarms, the switch block can consist of four switches arranged in pairs, with each pair designed to monitor one of the movable element positions. The switches in each pair can be connected to a single electrical circuit. This ensures that even in the event of a mechanical or electrical failure of one switch in the pair, the second switch in the same circuit will correctly generate the pointer position signal, preventing failure of the entire control system. To further enhance electrical reliability and safety, each switch can be equipped with a pair of bridge-type changeover contacts.

[0023] The yoke ensures sequential switching of switches as the shaft rotates. To achieve this, the yoke consists of two parts, each with a recess. The recess profile in the yoke's cross-section is triangular, ensuring the opening of the contacts of the corresponding switch when its interacting element (roller) enters the recess. The converging sides create a kinematic profile designed to eliminate hysteresis and ensure highly accurate switch actuation at a precisely defined angular position of the shaft.

[0024] The entry side of the triangular recess can be positioned at an angle of 15 to 25° to the yoke radius, passing through the intersection of this side with the circle describing the yoke. This gentle angle ensures smooth entry of the roller into the recess, eliminating shock loads and vibrations, and ensures high repeatability of the actuation point. To further reduce loads and improve actuation smoothness, a bevel can be installed at the entry side of the recess, adjacent to the entry side.

[0025] The stop side of the triangular recess is positioned at an angle of 40 to 45° to the yoke radius, passing through the intersection of this side with the circle describing the yoke. This angle forms a rigid stop that securely holds the switch's interacting element in its final position and prevents it from bouncing back after engagement. To further enhance control reliability under conditions of strong vibration, a groove can be additionally made in the recess. The groove, adjacent to the stop side, forms a locking protrusion that serves as a mechanical lock for the switch's interacting element.

[0026] The invention can be made from known materials using known means, which indicates its compliance with the patentability criterion of “industrial applicability”.

[0027] The invention is characterized by a previously unknown set of essential features from the prior art, distinguished in that a yoke is fixed to the shaft, having two working parts, on each of which a recess is made, wherein the profile of the recess in the cross-section of the yoke has a triangular shape, ensuring the opening of the contacts of the corresponding switch when its interacting element enters the said recess during rotation of the shaft.

[0028] The design of the actuator as a single yoke with two working parts enhances the device's structural reliability and stability. Unlike the prototype's complex, multi-component, and adjustable design, which consisted of two independent assemblies, the yoke has no internal moving parts, springs, or gear engagements. This eliminates numerous potential failure points associated with wear, contamination, or jamming of small components. Furthermore, the triangular shape of the recesses creates a clearly defined mechanical stability point for the interacting element (roller). This ensures high accuracy and repeatability of the switch actuation point, eliminating the cause of mechanical hysteresis.

[0029] The combination of essential features of the invention makes it possible to create a structurally simple and fault-tolerant unit, which, thanks to its triangular profile, ensures the kinematic elimination of hysteresis and dead zones.

[0030] This ensures the achievement of a technical result consisting of increasing the accuracy of the device for monitoring the position of the movable element of the switch by reducing the influence of mechanical hysteresis on the switch contacts.

[0031] The invention has a set of essential features previously unknown in the prior art, which indicates its compliance with the patentability criterion of “novelty”.

[0032] The invention is unknown in the prior art and does not clearly follow from it. Therefore, the invention meets the patentability criterion of "inventive step."

[0033] Implementation of the invention

[0034] The invention is explained by the following figures.

[0035] Fig. 1 – Device for monitoring the position of the movable element of the switch, a crank-and-rocker mechanism is attached to the shaft for connecting the shaft with the controlled movable element of the switch, the housing cover is dismantled, isometric view.

[0036] Fig. 2 – Device for monitoring the position of the movable element of the turnout, top view.

[0037] Fig. 3 – A bracket having a triangular recess, at the entrance to the recess there is a bevel, conjugated with the entrance side of the triangular recess, and the stop side of the recess has a groove made in the lower part of the recess and forming a locking protrusion for the interacting element (roller) of the switch, top view.

[0038] To illustrate the possibility of implementation and a more complete understanding of the essence of the invention, an embodiment of it is presented below, which can be changed or supplemented in any way, while the present invention is in no way limited to the presented embodiment.

[0039] A device for monitoring the position of a movable element of a switch comprises a housing consisting of a base 10 and a cover. A shaft 12 and two pairs of normally-closed switches 14 and 16 are fixed to the base 10. The switches are located on a single circle, the center of which coincides with the longitudinal axis of the shaft 12. Switch 14 is designed to monitor the pressed state of the movable element, and switch 16 is designed to monitor its retracted state. Switches 14 and 16 within each pair are included in a single electrical circuit for monitoring the corresponding position. Each of switches 14 and 16 contains a pair of bridge-type switching electrical contacts and spring-loaded interacting elements made in the form of rollers.

[0040] On the part of the shaft 12, located in the internal space of the housing 10, a yoke is rigidly fixed, having two working parts 18 and 20, each of which is located opposite the corresponding pair of switches 14 and 16. On each working part 18 and 20, a recess is made, intended for interaction with the switch rollers.

[0041] The cross-sectional profile of the specified recess has a triangular shape. The input side of the triangular recess is located at an angle β to the radius of the yoke, passing through the point of intersection of this side with the circle describing the yoke, while the magnitude of this angle is from 15 to 25°. At the entrance to the recess, formed by the input side, a bevel is formed, which is conjugated with it and with the side face of the yoke. The stop side of the triangular recess is located at an angle α to the radius of the yoke, while the magnitude of this angle is from 40 to 45°. A groove is formed in the lower part of the recess, adjacent to the stop side and forming a locking protrusion for the interacting element of the switch (roller).

[0042] At the end of shaft 12, located outside the interior of housing 10, is secured crank 22 of a crank-and-link mechanism, by means of which shaft 12 is connected to the controlled point. The crank-and-link mechanism is designed to adjust the working length of link 24 by means of an adjusting block 26 mounted thereon, to which crank 22 is pivotally attached.

[0043] The invention works as follows.

[0044] Before operation, the device is mounted on the turnout. The housing base 10 is secured to a fixed element, such as the mounting pad of the stock rail. The crank mechanism is connected via a link 24 to the controlled moving element, such as the switch point.

[0045] After installation, the device is adjusted. To do this, the movable element is set to one of its extreme positions, for example, pressed. Using the adjusting block 26 on the linkage 24, its working length is adjusted, achieving a position of the shaft 12 at which the rollers of the switches 14 enter the recess on the working part 18 of the yoke, causing them to actuate (open the contacts). The movable element is then moved to the other extreme (retracted) position, and similarly, the actuation of the switches 16 is verified by interaction with the recess on the working part 20 of the yoke. Once adjustments are complete, the device is ready for operation.

[0046] During operation, when the movable element is moved from the retracted position to the pressed position, its transverse movement is transmitted via the crank mechanism to shaft 12, causing it to rotate. At the beginning of this rotation, the rollers of switches 16, which control the retracted position, move out of their recess on the working section 20 of the yoke, causing their contacts to close. Shaft 12 then continues to rotate until the rollers of switches 14, which control the pressed position, reach the recess on section 18 of the yoke. Moreover, the chamfer at the entrance to the recess ensures a smooth initial entry of the roller and reduces wear on the yoke edge. When the roller enters the recess, the contacts of switches 14 open, signaling that the movable element has reached the pressed position. The entry side of the recess, positioned at a gentle angle β, ensures a smooth, controlled, and impact-free entry of the roller into the triangular recess. The stop side, positioned at a steeper angle α, acts as a stop. The locking protrusion formed by the groove prevents its spontaneous exit from the recess and securely locks the roller in its final position, effectively damping residual inertia and completely eliminating its rebound or spontaneous exit from the recess. This ensures repeatability of the actuation point and eliminates mechanical hysteresis.

[0047] When the switch is reversed, a similar process occurs: shaft 12 rotates in the opposite direction, contacts of switches 14 close, and contacts of switches 16 open, signaling the retracted position. If neither pair of switches 14 or 16 is open, this clearly indicates an intermediate (uncontrolled) position of the movable element. Using four switches in pairs reduces the risk of false alarms and increases the reliability of the control device. This redundancy ensures that if one switch in the pair fails, the second switch in the same circuit will correctly generate the switch position signal, preventing failure of the control device.

[0048] This ensures the achievement of a technical result consisting in increasing the accuracy of the device for monitoring the position of the movable element of the switch by reducing the influence of mechanical hysteresis on the contacts of the switches.

Claims

1. A device for monitoring the position of a movable element of a switch, comprising a housing in which a shaft and a switch unit are secured, consisting of at least two switches, one of which ensures monitoring of the pressed state of the movable element of the switch, and the second ensures monitoring of the retracted state of the movable element of the switch, characterized in that a yoke is secured to the shaft, having two working parts, on each of which a recess is made, wherein the profile of the recess in the cross-section of the yoke has a triangular shape, ensuring the opening of the contacts of the corresponding switch when its interacting element enters the said recess during rotation of the shaft.

2. The device according to paragraph 1, characterized in that the switch block consists of four switches, combined in pairs, where each pair is intended to control one of the positions of the movable element of the switch, and the switches in each pair are included in one electrical circuit for controlling the corresponding position.

3. The device according to paragraph 1, characterized in that a crank-and-rocker mechanism is fixed to the shaft for connecting the shaft with the controlled movable element of the switch.

4. The device according to paragraph 1 or 2, characterized in that each switch contains a pair of bridge-type switching electrical contacts.

5. The device according to claim 1, characterized in that the input side of the triangular recess is located at an angle of 15 to 25° to the radius of the yoke, passing through the point of intersection of this side with the circle describing the yoke.

6. The device according to paragraph 1, characterized in that the stop side of the triangular recess is located at an angle of 40 to 45° to the radius of the yoke, passing through the point of intersection of this side with the circle describing the yoke.

7. The device according to paragraph 5, characterized in that at the entrance to the recess there is a bevel connected to the entrance side of the triangular recess.

8. The device according to claim 1, characterized in that the stop side of the recess has a groove made in the lower part of the recess and forming a locking protrusion for the interacting element of the switch.

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