Single chambered pull cord sensor

Abstract

This utility model relates to a single-cavity pull-cord sensor, which includes a housing, a winding wheel disposed within the inner cavity of the housing, a measuring component, and a coil spring. The internal space of the winding wheel is divided into an upper concave cavity and a lower concave cavity by a horizontally arranged partition. The measuring component is placed in the upper concave cavity, and the coil spring is placed in the lower concave cavity. Compared with the prior art, this utility model has the advantages of compact structure, small size, and high space utilization.

Description

Technical Field

[0001] This utility model relates to the field of sensor design, and in particular to a single-cavity pull-rope sensor. Background Technology

[0002] Existing draw rope sensors typically employ a three-chamber design. The first chamber is the electronic chamber, located at the top of the draw rope sensor housing. This chamber contains a circuit board (usually an encoder) to perform the conversion from angle to length and output the final digital or analog signal. The second chamber is the winding wheel chamber, located in the middle of the draw rope sensor housing, which contains a winding wheel for winding the steel wire rope. The third chamber is the coil spring chamber, located at the bottom of the draw rope sensor housing. This chamber contains a coil spring to provide a continuous reverse rebound force to the winding wheel.

[0003] In this three-chamber design, the three chambers are independent and not connected. The height of the entire pull rope sensor product is the sum of the heights of the three chambers, and it's difficult to reduce the height further. Furthermore, the largest part of the entire pull rope sensor is the winding wheel, and the longer the total length of the wire rope, the larger the diameter of the winding wheel. The result of combining the three chambers is often a large winding wheel chamber with a smaller spring chamber and an even smaller circuit chamber, which looks aesthetically displeasing. Alternatively, if the circuit chamber, winding wheel chamber, and spring chamber could be made to the same size, the appearance would be more harmonious, but at least a large portion of the space within the circuit chamber would be wasted.

[0004] When applications require space constraints or strict height restrictions, the three-chamber structure sensor cannot be installed and used. Therefore, it is necessary to develop a compact, height-reducing pull-wire sensor product. Utility Model Content

[0005] To address the technical problems in the background art, this utility model provides a single-cavity pull rope sensor with a compact structure, small size, and high space utilization, including a housing, a winding wheel disposed in the inner cavity of the housing, a measuring component, and a coil spring. The internal space of the winding wheel is divided into an upper concave cavity and a lower concave cavity by a horizontally arranged partition. The measuring component is placed in the upper concave cavity, and the coil spring is placed in the lower concave cavity.

[0006] Furthermore, the measuring component and the coil spring are connected by a drive shaft, and the drive shaft is fixedly connected to the partition or integrally formed.

[0007] Furthermore, the measuring component includes a circuit board, a bracket, and a gear set. The bracket is U-shaped and is fixed together with the circuit board to the lower surface of the top plate of the housing by screws. The gear set includes a driving gear and a driven gear that mesh with each other. The driven gear is rotatably mounted on the bracket and has a first magnet on it. The driving gear is mounted on the top of the driving shaft and has a second magnet on it.

[0008] Furthermore, the circuit board is provided with a microcontroller and a first magnetic encoder chip and a second magnetic encoder chip that communicate with the microcontroller respectively. The first magnetic encoder chip and the second magnetic encoder chip are both disposed on the lower surface of the circuit board and are respectively disposed opposite to the second magnet and the first magnet.

[0009] Furthermore, the number of teeth of the driving gear and the driven gear are coprime.

[0010] Furthermore, a stepped shaft is installed at the bottom of the drive shaft, the inner hook of the coil spring is fixed to the first mounting groove of the stepped shaft, and the outer hook is fixed to the second mounting groove on the bottom convex plate of the housing.

[0011] Furthermore, a steel wire rope is wound around the surface of the winding part of the winding wheel, one end of the steel wire rope is fixed to the winding part, and the other end extends out from the outlet end and is fixed with a pull ring.

[0012] Furthermore, the outlet end is disposed on the side wall of the housing.

[0013] Furthermore, when using this single-cavity pull-rope sensor for length measurement, when the object to be measured moves in a straight line, the steel wire rope is pulled out. The steel wire rope drives the winding wheel to rotate, which in turn drives the prime number drive gear and the drive magnet to rotate synchronously through the drive shaft, and at the same time drives the driven gear and the driven magnet to rotate synchronously. At this time, the first magnetic encoder chip detects the angle a1 of the drive magnet, and the second magnetic encoder chip detects the angle a2 of the driven magnet. The total length of the steel wire rope pulled out is calculated, which is the linear displacement of the object to be measured.

[0014] Furthermore, obtaining the total length of the steel wire rope pulled out specifically includes the following steps:

[0015] 1) Obtain the angle a1 of the active magnet and the angle a2 of the driven magnet at the current position respectively. Set the initial position of both the active and driven gears to 0 degrees.

[0016] 2) Calculate the theoretical angle difference Δa, then we have:

[0017]

[0018] Where n1 and n2 are the number of teeth of the driving gear and the driven gear, respectively, and % represents the remainder operation;

[0019] 3) Calculate the total number of revolutions N of the drive shaft based on the theoretical angle difference Δa, then we have:

[0020] when or If the total number of revolutions N of the drive shaft is 0, then it is determined that the total number of revolutions N is 0.

[0021] Otherwise, calculate to satisfy the condition. When N∈[1,n2-1], the corresponding total number of revolutions N of the drive shaft is;

[0022] 4) Calculate the total length L pulled out of the wire rope, then:

[0023]

[0024] Where R is the winding radius of the winding wheel.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] Compared to the existing three-cavity structure of the pull-wire sensor (electronic cavity, winding wheel cavity, and coiled spring cavity), this invention effectively utilizes the internal space of the winding wheel. Through ingenious design, the space occupied by the measuring components and the coiled spring is effectively incorporated into the upper and lower concave cavities of the winding wheel. This transforms the original three-cavity structure into a single winding wheel cavity, reducing the height of the existing pull-wire sensor to the height of a single winding wheel cavity. This significantly reduces the height and volume, improves the utilization rate of internal space, and enables the measurement function of the pull-wire sensor, which previously required three cavities, to be achieved with only a single cavity. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of a single-cavity pull-rope sensor according to the present invention;

[0028] Figure 2 This is a flowchart illustrating a method for measuring the linear displacement of an object using a single-cavity pull-rope sensor according to this invention.

[0029] Explanation of reference numerals in the attached figures:

[0030] 1. First magnetic encoder chip; 2. Microcontroller; 3. Circuit board; 4. Second magnetic encoder chip; 5. First magnet; 6. Second magnet; 7. Drive gear; 8. Driven gear; 9. Bracket; 10. Screw; 11. Drive shaft; 12. Stepped shaft; 13. Coil spring; 14. Winding wheel; 15. Lower cavity; 16. Upper cavity; 17. Wire rope; 18. Housing; 19. Outlet end; 20. Pull ring. Detailed Implementation

[0031] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. This embodiment is based on the technical solution of the present invention and provides detailed implementation methods and specific operating procedures; however, the scope of protection of the present invention is not limited to the following embodiments.

[0032] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0033] In the description of this embodiment, it should be noted that the terms "upper", "lower", "inner", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the utility model product is usually placed in during use. They are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the utility model.

[0034] The terms “first”, “second”, etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0035] In the description of this embodiment, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set up," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment based on the specific circumstances.

[0036] To make the objectives, technical solutions, and advantages of this utility model clearer, the embodiments of this utility model will be described in further detail below with reference to the accompanying drawings.

[0037] Example

[0038] This invention provides a single-cavity pull-rope sensor, which improves and optimizes the design of the three cavities of the existing pull-rope sensor, and finally realizes all functions in a single cavity, thereby greatly reducing the total height and volume of the pull-rope sensor, making it suitable for occasions with strict restrictions on installation height and space.

[0039] like Figure 1As shown, the single-cavity pull rope sensor includes a separate housing 18 (which can be cylindrical or other cylindrical shapes), a winding wheel 14 disposed in the inner cavity of the housing 18, and a measuring component and a coil spring 13 disposed in the inner space of the winding wheel 14 respectively.

[0040] The main view of the winding reel 14 is I-shaped, and its internal space is divided into an upper cavity 16 and a lower cavity 15 by a horizontally arranged partition. The upper cavity 16 is used to provide a space for the measuring component, and the lower cavity 15 is used to provide a space for the coil spring 13.

[0041] The measuring assembly includes a circuit board 3, a bracket 9, and a gear set. The circuit board 3 houses a microcontroller 2 and a first magnetic encoder chip 1 and a second magnetic encoder chip 4, which communicate with the microcontroller 2. The first magnetic encoder chip 1 and the second magnetic encoder chip 4 are respectively disposed on the lower surface of the circuit board 3. The bracket 9 is U-shaped and is fixed to the lower surface of the top plate of the pull-wire sensor housing 18 by means of ear plates on both sides and screws 10. The gear set includes a driving gear 7 and a driven gear 8 that mesh with each other. The driving gear 7 is mounted on the top of the drive shaft 11, and a drive gear 8 is embedded on the upper surface of the driving gear 7. A magnetic encoder chip 1 is positioned opposite a first magnet 5. A driven gear 8 is rotatably mounted on a bracket 9 via a driven gear shaft. A second magnet 6, which is positioned opposite a second magnetic encoder chip 4, is embedded on the upper surface of the driven gear 8. Both the first magnet 5 and the second magnet 6 are flat magnets. When the drive shaft 11 drives the drive gear 7 and the first magnet 5 to rotate, the meshing driven gear 8 and the second magnet 6 also rotate synchronously. At this time, the first magnetic encoder chip 1 and the second magnetic encoder chip 4 respectively detect the corresponding magnetic field changes and thus detect the rotation angle of the drive gear 7 and the driven gear 8.

[0042] The upper end of the drive shaft 11 passes through the partition of the winding wheel 14 and the bracket 9 respectively, and the drive shaft 11 and the winding wheel 14 are fixedly connected by the partition to achieve synchronous rotation. The lower end of the drive shaft 11 is provided with a threaded hole, which is screwed and installed with the stepped shaft 12 at the bottom.

[0043] The coil spring 13 is installed in the recessed cavity 15. Its inner hook is fixed to the first mounting groove of the stepped shaft 12, and its outer hook is fixed to the second mounting groove on the convex plate on the bottom surface of the outer casing 18. It is used to provide the reverse force for the winding wheel. One end of the measuring wire rope 17 is fixed to the surface of the winding wheel 14 and then wound around the surface of the winding wheel 14 (it can be a single layer or multiple layers, depending on the product range and the size of the winding wheel). The other end is led out from the wire outlet 19 fixed to the side of the outer casing 18 and a pull ring 20 is fixed thereon.

[0044] In use, the pull-string sensor of this invention involves attaching the pull ring 20 to the object being measured. When the object moves linearly, the steel wire rope 17 is pulled out from the outlet end 19 via the pull ring 20. The steel wire rope 17 then drives the winding wheel 14 to rotate. At this time, the coil spring 13 provides a counterforce to the winding wheel 14 through the stepped shaft 12 and the drive shaft 11, thus ensuring that the steel wire rope 17 remains taut throughout the pulling process. The rotation of the winding wheel 14 drives the drive gear 7 to rotate via the drive shaft 11, thereby causing the drive magnet 6 to rotate along with the drive gear 7. Synchronous rotation, due to mutual meshing, the rotation of the driving gear 7 also drives the driven gear 8 to rotate, thus causing the driven magnet 5 to rotate synchronously with the driven gear 8. At this time, the first magnetic encoder chip 1 detects the angle a1 of the driving magnet 6, and the second magnetic encoder chip 4 detects the angle a2 of the driven magnet 5. In this example, the number of teeth of the driving gear 7 and the driven gear 8 are set to be prime numbers (e.g., prime pairs such as 37 and 47, 13 and 29). The total number of rotations and the total angle of the driving shaft 11 can be calculated from the angles detected by the two magnetic encoder chips. After obtaining the total number of rotations N of the driving shaft 11, combined with the winding radius R of the winding wheel 14 and the angle a1, the total length L pulled out by the wire rope 17 can be calculated, that is, the linear displacement of the object to be measured. Figure 2 As shown, the specific steps include:

[0045] 1) Obtain the angle a1 of the active magnet 6 and the angle a2 of the driven magnet 5 respectively. In this example, it is assumed that the initial position of both the active gear and the driven gear is 0 degrees.

[0046] 2) Calculate the theoretical angle difference Δa, then we have:

[0047]

[0048] Where n1 and n2 are the number of teeth of the driving gear and the driven gear, respectively, and % represents the remainder operation;

[0049] 3) Calculate the total number of revolutions N of the drive shaft based on the theoretical angle difference Δa, then we have:

[0050] when or If the total number of revolutions N of the drive shaft is 0, then it is determined that the total number of revolutions N is 0.

[0051] Otherwise, calculate to satisfy the condition. When N∈[1,n2-1], the corresponding total number of revolutions N of the drive shaft is;

[0052] 4) Calculate the total length L pulled out of the wire rope, then:

[0053]

[0054] In summary, when designing the size of the outer shell 18, the size of the outer shell 18 mainly depends on the size of the winding wheel 14, or on the total length and thickness of the wire rope 17, without having to consider the height and volume of the coil spring cavity and the circuit cavity. This greatly reduces the overall volume of the product, making the height of the product only the size of the winding wheel cavity of the original product. Furthermore, the present invention achieves the measurement function of the rope-pulling sensor, which originally required three cavities, within only a single cavity of the outer shell 18.

[0055] The preferred embodiments of this utility model have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of this utility model without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of this utility model through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A single-cavity pull-wire sensor, characterized in that, Includes a housing (18), a winding wheel (14) disposed in the inner cavity of the housing (18), a measuring component and a coil spring (13). The inner space of the winding wheel (14) is divided into an upper cavity (16) and a lower cavity (15) by a transversely arranged partition. The measuring component is placed in the upper cavity (16) and the coil spring (13) is placed in the lower cavity (15).

2. The single-cavity pull-wire sensor according to claim 1, characterized in that, The measuring component and the coil spring (13) are connected by a drive shaft (11), which is fixedly connected to the partition or integrally formed.

3. A single-cavity pull-wire sensor according to claim 2, characterized in that, The measuring assembly includes a circuit board (3), a bracket (9), and a gear set. The bracket (9) is U-shaped and is fixed to the lower surface of the top plate of the housing (18) together with the circuit board (3) by screws (10). The gear set includes a driving gear (7) and a driven gear (8) that mesh with each other. The driven gear (8) is rotatably mounted on the bracket (9) and has a first magnet (5) on it. The driving gear (7) is mounted on the top of the driving shaft (11) and has a second magnet (6) on it.

4. A single-cavity pull-wire sensor according to claim 3, characterized in that, The circuit board (3) is provided with a microcontroller (2) and a first magnetic encoder chip (1) and a second magnetic encoder chip (4) that communicate with the microcontroller (2) respectively. The first magnetic encoder chip (1) and the second magnetic encoder chip (4) are both disposed on the lower surface of the circuit board (3) and are respectively disposed opposite to the second magnet (6) and the first magnet (5).

5. A single-cavity pull-wire sensor according to claim 3, characterized in that, The number of teeth of the driving gear (7) and the driven gear (8) are coprime.

6. A single-cavity pull-wire sensor according to claim 2, characterized in that, A stepped shaft (12) is installed at the bottom of the drive shaft (11). The inner hook of the coil spring (13) is fixed to the first mounting groove of the stepped shaft (12), and the outer hook is fixed to the second mounting groove on the bottom convex plate of the outer shell (18).

7. A single-cavity pull-wire sensor according to claim 1, characterized in that, The winding part of the winding wheel (14) is wound with a steel wire rope (17). One end of the steel wire rope (17) is fixed to the winding part, and the other end extends out from the wire outlet (19) and is fixed with a pull ring (20).

8. A single-cavity pull-wire sensor according to claim 7, characterized in that, The outgoing terminal (19) is located on the side wall of the outer casing (18).

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