Pull rope sensor with sealing structure

Abstract

The invention discloses a pull rope sensor with a sealing structure, which belongs to the technical field of displacement sensors, and comprises a shell, two ends of which are provided with counter bores and a through hole penetrating through the two counter bores along the axis; the two ends of the shell are connected with a rotating wheel cover plate and a spring cover plate respectively to form a rotating wheel cavity and a spring cavity respectively. A notch is formed in the side face of the rotating wheel cover plate or the shell. The rotation angle sensor is arranged at the end, away from the spring cavity, of the spring cover plate, and the spring cover plate is provided with a measuring channel along the axis; one end of the rotating shaft penetrates through the through hole, and the other end penetrates through the measuring channel to be connected with the rotation angle sensor; the spring is arranged in the spring cavity, one end of the spring is fixedly connected with the rotating shaft, and the other end is connected with the spring fixing column; the spring fixing column is fixedly arranged between the shell and the spring cover plate and is not coaxial with the rotating shaft; the rotating wheel is arranged in the rotating wheel cavity and fixedly connected with one end of the rotating shaft; one end of the pull rope is fixedly connected with the rotating wheel and wound on the rotating wheel, and the other end of the pull rope extends out of the notch and is connected with a measured object. The sensor can realize absolute position measurement within a certain range.

Description

Technical Field

[0001] This invention relates to the field of displacement sensor technology, specifically a sealed pull-rope sensor. Background Technology

[0002] In engineering practice, it is often necessary to measure absolute displacement or position, that is, to measure the displacement of the measured object relative to a predetermined reference or its position in a predetermined coordinate system. Furthermore, in engineering practice, power supply may be interrupted for various reasons during equipment operation. If the power outage is prolonged, the equipment may require manual operation during the power outage. In such cases, continuous monitoring and measurement using sensors is not feasible. For example, in factories and mines, for economic reasons, there are many manual turnouts. When a turnout needs to be switched, an operator goes to the turnout and manually operates it as needed. If the turnout is in the required position and state, no operation is necessary. Therefore, it is necessary to monitor the real-time position and status of the manual turnouts. Since there are situations where the turnout position and status monitoring equipment loses power, and the turnout may be moved during the power outage, the turnout position and status monitoring equipment needs to immediately output the current position and status of the turnout based on the measured information after power is restored. However, when the equipment is powered back on, the values ​​measured by incremental sensors may be inaccurate and cannot accurately reflect the displacement or position of the measured object. Summary of the Invention

[0003] The purpose of this invention is to provide a sealed structure pull rope sensor that can measure the absolute displacement or position information of the object being measured in real time under power failure and restart conditions.

[0004] The technical solution of this invention is: A sealed pull-wire sensor, comprising: The housing has countersunk holes at both ends and through holes passing through the two countersunk holes along the axis; a wheel cover plate and a spring cover plate are respectively connected to the two ends of the housing, forming a wheel cavity and a spring cavity respectively; a slot is opened on the side of the wheel cover plate or the housing; An angle sensor is disposed at the end of the spring cover plate away from the spring cavity, and the spring cover plate is provided with a measuring channel along the axis. A rotating shaft, one end of which passes through the through hole and the other end of which passes through the measuring channel, measures the rotation angle through the rotation angle sensor; A spring is disposed within the spring cavity, with one end fixedly connected to the rotating shaft and the other end connected to a spring fixing post; the spring fixing post is fixedly disposed between the housing and the spring cover plate, and is not coaxial with the rotating shaft; A rotating wheel is disposed inside the rotating wheel cavity and is fixedly connected to one end of the rotating shaft; A pull rope, one end of which is fixedly connected to the rotating wheel and wound around the rotating wheel, and the other end of which extends out from the slot and is connected to the object being measured.

[0005] Preferably, it further includes: A sealing element is fixedly disposed within the through hole and located on the side close to the wheel cavity; The first bearing is fixedly installed inside the through hole; The second bearing is fixedly installed in the measuring channel of the spring cover plate; one end of the rotating shaft passes through the first bearing and the seal, and is fixedly connected to the rotating wheel and rotatably connected to the first bearing and the seal; the other end of the rotating shaft passes through the spring and is fixedly mounted on the second bearing.

[0006] Preferably, the angle sensor is an angular displacement encoder; the other end of the rotating shaft is connected to the input end of the angular displacement encoder.

[0007] Preferably, the angle sensor is a non-contact angular displacement sensor; a detection target is fixedly mounted on the rotating shaft, the detection device of the angle sensor is aligned with the detection target, the detection target is a color mark or a magnetic material, and the sensor is an optical angle sensor, a magnetoresistive angle sensor, or a Hall sensor.

[0008] Preferably, the housing is a multi-faceted cylindrical shape, with at least two fixing threaded holes on each face for fixing the sealing structure pull rope sensor body.

[0009] Preferably, each end face of the housing has at least two threaded holes for fixing the wheel cover and the spring cover.

[0010] Preferably, the center of the wheel has a hole that is fixedly fitted with the shaft; the outer periphery of the wheel has a rope groove for accommodating the rope, and the rope groove has a connecting hole formed by a radial hole and an axial hole for fixing the rope connector; the disc surface of the wheel has a weight reduction groove; the slot on the side of the wheel cover or housing is tangent to the rope groove.

[0011] Preferably, the spring cover has a plate-shaped flange end, the outer periphery of which matches the outer periphery of the housing, the flange end has a stepped stop, the stepped stop matches and positions with the countersunk hole on the housing where the spring is placed; the center of the flange end has a bearing hole for fixing the second bearing, and the other end has a sensor mounting hole for fixing and accommodating the angle sensor; the sensor mounting hole communicates with the bearing hole.

[0012] The beneficial effects of this invention are: This invention proposes a sealed pull-cord sensor that employs a closed pull-cord wheel structure combined with an elastic reset structure. It converts the measurement of linear displacement into the measurement of angular displacement. Based on the linear relationship between arc length and angle, the linear displacement of the pull-cord following the measured object is calculated from the measured angle change. Since the measured angle value is an absolute value, the calculated displacement value is also equivalent to an absolute value. The linear displacement value corresponding to each angular position is fixed. This solves the problem of potential errors in the values ​​measured by sensors using relative values ​​when power is cut off and then restored in existing detection equipment, i.e., the inability to accurately reflect the displacement or position of the measured object. Furthermore, the sealed structure improves reliability in outdoor environments. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall structure of a sealed pull-rope sensor according to the present invention.

[0014] In the diagram, 1 is the wheel cover plate; 2 is the wheel; 3 is the pull rope; 4 is the seal; 5 is the housing; 6 is the first bearing; 7 is the spring; 8 is the second bearing; 9 is the angle sensor; 10 is the spring cover plate; 11 is the magnetic column; 12 is the rotating shaft; and 13 is the spring fixing column. Detailed Implementation

[0015] The following is combined Figure 1 The specific embodiments of the present invention will be described in detail below. In the description of the invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0016] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; in the description of the invention, unless otherwise stated, "a plurality of" means two or more.

[0017] Example 1 like Figure 1 As shown, Figure 1This is a structural diagram. An embodiment of the present invention provides a sealed pull-rope sensor, including a housing 5, an angle sensor 9, a rotating shaft 12, a spring 7, a rotating wheel 2, and a pull rope 3. The housing 5 is cylindrical, with countersunk holes at both ends and a through hole along its axis, the through hole passing through the two countersunk holes; a rotating wheel cover plate 1 and a spring cover plate 10 are respectively connected to both ends of the housing 5, forming a rotating wheel cavity and a spring cavity respectively; a slot is provided on the side of the rotating wheel cover plate 1 or the housing 5 to accommodate the pull rope 3 extending out.

[0018] Angle sensor 9 is located at the end of spring cover plate 10 away from the spring cavity. Spring cover plate 10 has a measurement channel along its axis. One end of rotating shaft 12 passes through a through hole, and the other end passes through the measurement channel and connects to angle sensor 9. Specifically, the invention also includes a seal 4, a first bearing 6, and a second bearing 8, serving as a sealing structure and supporting bearings for rotating shaft 12. The seal 4 is fixedly installed in the through hole and located near the rotating wheel cavity. The first bearing 6 is fixedly installed in the through hole. The second bearing 8 is fixedly installed in the measurement channel of spring cover plate 10. One end of rotating shaft 12 passes through the first bearing 6 and the seal 4, is fixedly connected to rotating wheel 2, and is rotatably connected to the first bearing 6 and the seal 4. The other end of rotating shaft 12 passes through spring 7 and is fixedly mounted on the second bearing 8. Rotating wheel 2 is located in the rotating wheel cavity and is fixedly connected to one end of rotating shaft 12. One end of pull rope 3 is fixedly connected to rotating wheel 2 and wound around rotating wheel 2, while the other end extends from the slot and connects to the object being measured. Spring 7 is set inside the spring cavity, with one end fixedly connected to housing 5 or spring cover plate 10, and the other end fixedly connected to rotating shaft 12.

[0019] Among them, the angle sensor 9 for detecting rotation angle can be contact or non-contact, such as an angular displacement encoder or a magnetoresistive angular displacement sensor. If it is a contact type, the sensor's detection shaft and the rotating shaft are fixedly connected. If it is a non-contact type, a detection target, such as a magnetic column or color block, is fixedly installed on the rotating shaft. The detection device on the sensor is aligned with the target and detects the angle change to reflect the angle change of the rotating shaft. The angle detection sensor can integrate a calculation module, which is used to calculate the tensile displacement based on the relationship between the angle and the rope displacement.

[0020] Furthermore, a spring fixing post 13 is fixedly installed on the housing 5 or the spring cover plate 10; one end of the spring 7 is fixed to the spring fixing post 13, and the other end is fixed to the rotating shaft 12. The spring is a torsion spring or a coil spring, etc. When the pull rope extends, the rotating wheel drives the rotating shaft to rotate, the spring stores energy, and keeps the pull rope taut (straight) during the extension and retraction process.

[0021] The housing 5 is a multi-faceted cylindrical shape, with at least two threaded holes on each face for fixing the sealing structure pull rope sensor body. Both end faces of the housing 2 have at least two threaded holes for fixing the rotary cover plate 1 and the spring cover plate 10. The spring cavity of the housing 2 has a countersunk hole for inserting a spring fixing post.

[0022] The center of the wheel 2 has a hole that is fixedly fitted with the shaft 12; the outer periphery of the wheel 2 is provided with a rope groove for accommodating the rope, and the rope groove has a connecting hole formed by a radial hole and an axial hole for fixing the rope connector; the disc surface of the wheel 2 has a weight-reducing groove to reduce the moment of inertia.

[0023] The outer circumference of the wheel cover plate 1 matches the outer circumference of the shell 5. A countersunk hole is located on the side of the wheel that is in contact with the shell 5. A groove is cut into the wall of the countersunk hole, connecting the countersunk hole to the outside. The groove is tangent to the pull rope groove on the wheel 2. When the pull rope 3 extends or retracts along the groove direction, it forms a tangent relationship with the circle formed by the pull rope on the wheel. In another embodiment, the wheel cover plate 1 is a plate-like structure without a countersunk hole or groove; the groove is located on the shell 5.

[0024] The spring cover 10 has a plate-shaped flange end, the outer periphery of which matches the outer periphery of the housing 5. The flange end has a stepped stop, which matches and positions with the countersunk hole on the housing 5 where the spring is placed. The center of the flange end has a bearing hole for fixing the second bearing 8, and the other end has a sensor mounting hole for fixing and accommodating the angle sensor 9. The sensor mounting hole communicates with the bearing hole.

[0025] In another embodiment, there is only one countersunk hole in the spring cover plate 10 or the housing 5 for inserting the spring fixing post, and only one end of the spring fixing post needs to be inserted. In another embodiment, the countersunk hole in the spring cover plate 10 or the housing 5 for inserting the spring fixing post is a threaded hole, and the threaded end of the spring fixing post is screwed into this threaded hole.

[0026] The rotating shaft 12 is a stepped shaft, with one end connected to the rotating wheel 3 and the other end fixedly mounted with a magnetic marker as a rotation angle detection target. Both ends are supported by a first bearing 6 and a second bearing 8, respectively. The end with the rotation angle detection target has an axial groove into which one end of a coil spring is inserted. In another embodiment, this groove becomes a hole, into which one torsion arm of a torsion spring passes. Furthermore, a reflective marker is mounted on the end of the rotating shaft 12 as a target for a photoelectric sensor. Further, the end of the rotating shaft 12 is connected to the sensor's detection shaft via a transmission connection, forming a contact-type rotation angle measurement structure.

[0027] The radial dimension of the structure is determined by the outer diameter of the wheel 2. The outer diameter of the wheel 2 is determined by the displacement s to be measured. If the pull rope 3 is tightly wound around the surface of the groove in the wheel groove, the circumference of the center of the pull rope 32 is r. The absolute angular displacement measurement range of the angle sensor is 0 degrees to 180 degrees, then πr > s. The absolute angular displacement measurement range of the angle sensor is 0 degrees to 360 degrees, then 2πr > s.

[0028] This invention shares a similar principle with existing pull-cord sensor technology, converting linear displacement measurement into angular displacement measurement. Based on the linear relationship between arc length and angle, the linear displacement of the pull cord 3 along with the measured object is calculated from the measured angle change. To achieve absolute linear displacement measurement, the corresponding measurement angle in this invention does not exceed 180 degrees or 360 degrees. Thus, the measured angle value is an absolute value, and the calculated displacement value is also an absolute value, with a fixed linear displacement value at each angular position. This invention also incorporates a sealed structure to improve reliability in outdoor environments. Furthermore, this invention proposes using a non-contact magnetic sensor for angle measurement; compared to contact measurement structures, the rotation of the shaft 12 is unaffected by the sensor.

[0029] The above-disclosed embodiments are merely preferred embodiments of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A sealed pull-rope sensor, characterized in that, include: The housing (5) has countersunk holes at both ends and through holes passing through the two countersunk holes along the axis; the two ends of the housing (5) are respectively connected to a wheel cover plate (1) and a spring cover plate (10), forming a wheel cavity and a spring cavity respectively; the wheel cover plate (1) or the side of the housing (5) is provided with a slot; An angle sensor (9) is disposed at the end of the spring cover plate (10) away from the spring cavity, and the spring cover plate (10) is provided with a measuring channel along the axis; A rotating shaft (12) has one end passing through the through hole and the other end passing through the measuring channel, and the rotation angle is measured by the rotation angle sensor (9); A spring (7) is disposed in the spring cavity, one end of which is fixedly connected to the rotating shaft (12), and the other end is connected to the spring fixing post (13); the spring fixing post (13) is fixedly disposed between the housing (5) and the spring cover plate (10), and is not coaxial with the rotating shaft (12); A rotating wheel (2) is disposed in the rotating wheel cavity and is fixedly connected to one end of the rotating shaft (12); A pull rope (3) has one end fixedly connected to the rotating wheel (2) and wound around the rotating wheel (2), while the other end extends out from the slot and connects to the object being measured.

2. The sealed structure pull-rope sensor according to claim 1, characterized in that, Also includes: The sealing element (4) is fixedly disposed in the through hole and located on the side close to the wheel cavity; The first bearing (6) is fixedly installed in the through hole; The second bearing (8) is fixedly installed in the measuring channel of the spring cover plate (10); one end of the rotating shaft (12) passes through the first bearing (6) and the seal (4), is fixedly connected to the rotating wheel (2), and is rotatably connected to the first bearing (6) and the seal (4); the other end of the rotating shaft (12) passes through the spring (7) and is fixedly mounted on the second bearing (8).

3. The sealed structure pull-rope sensor according to claim 1, characterized in that, The angle sensor (9) is an angular displacement encoder; the other end of the rotating shaft (12) is connected to the input end of the angular displacement encoder.

4. The sealed structure pull-rope sensor according to claim 1, characterized in that, The angle sensor (9) is a non-contact angular displacement sensor; a detection target is fixedly installed on the rotating shaft (12), and the detection device of the angle sensor (9) is aligned with the detection target. The detection target is a color mark or a magnetic material, and the sensor is an optical angle sensor, a magnetoresistive angle sensor, or a Hall sensor.

5. The sealed structure pull-rope sensor according to claim 1, characterized in that, The housing (5) is multi-faceted cylindrical in shape, with at least two fixed threaded holes on each face for fixing the sealing structure pull rope sensor body.

6. The sealed structure pull-rope sensor according to claim 1, characterized in that, The housing (2) has at least two threaded holes on both end faces for fixing the wheel cover (1) and the spring cover (10).

7. The sealed structure pull-rope sensor according to claim 1, characterized in that, The center of the wheel (2) has a hole that is fixedly fitted with the shaft (12); the outer periphery of the wheel (2) is provided with a rope groove for accommodating the rope, and the rope groove has a connecting hole formed by a radial hole and an axial hole for fixing the rope connector; the disc surface of the wheel (2) has a weight reduction groove; the slot on the side of the wheel cover plate (1) or the housing (5) is tangent to the rope groove.

8. The sealed structure pull-rope sensor according to claim 5, characterized in that, The spring cover plate (10) has a plate-shaped flange end, the outer periphery of which matches the outer periphery of the housing (5). The flange end has a stepped stop, which matches and positions with the countersunk hole on the housing (5) where the spring is placed. The center of the flange end has a bearing hole for fixing the second bearing (8), and the other end has a sensor mounting hole for fixing and accommodating the angle sensor (9). The sensor mounting hole communicates with the bearing hole.

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