Self-compensating corded encoder

Abstract

The application provides an automatic compensation pull rope encoder, and belongs to the technical field of pull rope encoders. The automatic compensation pull rope encoder comprises a measuring wheel with a single row of pull rope winding, one end of the pull rope is connected with an elastic compensation part, the elastic compensation part is connected with a target object to be measured; one end of the rotating shaft of the measuring wheel is connected with a deformation part, the other end of the rotating shaft of the measuring wheel is connected with a rotary encoder; the deformation part is deformed to store energy; when the target object to be measured approaches the measuring wheel, the deformation part drives the measuring wheel to rotate reversely to recover the pull rope; the rotation of the measuring wheel drives the rotary encoder to rotate, and distance measurement is realized; wherein the elastic force generated by the deformation of the deformation part is equal to the elastic force when the elastic compensation part pulls the pull rope, and the error caused by the smaller winding of the pull rope on the measuring wheel is compensated. The application uses an automatic compensation mode, reduces the layering error caused by the multi-turn winding in the existing pull rope encoder, has a simple structure, hardly affects the volume and manufacturing cost of the sensor, and improves the precision of the pull rope encoder.

Description

Technical Field

[0001] This invention relates to the field of draw rope encoder technology, and more specifically to an automatic compensation draw rope encoder. Background Technology

[0002] A draw-wire encoder, also known as a draw-wire displacement sensor, draw-wire sensor, draw-wire electronic ruler, etc., combines the advantages of angle sensors and linear displacement sensors. It is a linear displacement sensor with a compact structure, long measuring stroke, high measurement accuracy, reliable performance, and low cost.

[0003] Draw-wire encoders are mainly used in linear guide systems, hydraulic cylinder systems, telescopic systems, hollow blow molding machines, IT equipment, tension regulation, high-speed automatic feeders, speed regulation, warehouse positioning, pressure machinery, papermaking machinery, textile machinery, metal sheet machinery, paper packaging machinery, printing machinery, level controllers, construction machinery, gate opening measurement, and other related dimensional measurement and position control applications. They are also widely used in screen display and digital display systems in the testing machine industry, and their prospects are very promising.

[0004] A draw-wire encoder detects and measures linear position and speed using a flexible draw-wire and a spring-loaded spool. It mainly consists of four parts: a measuring wire, a spool, a spring, and a rotary sensor. Its working principle is as follows: Inside the sensor housing, a stainless steel draw-wire is wound around a precision-machined straight cylindrical spool, which serves as both a measuring wire spool and an unwinding spool. To maintain the draw-wire tension, a spring is coupled to the spool. The spool is then coupled to the shaft of a rotary sensor (encoder or potentiometer). As the sensor's draw-wire extends along a movable object, the spool and sensor shaft rotate. The rotating shaft generates an electronic signal proportional to the linear extension or speed of the draw-wire.

[0005] Currently, most pull-cord encoders on the market use a design where the encoder's rotating shaft and the winding reel are coaxial. Because the winding reel is wider than the wire rope, irregular layering of the wire rope occurs on the reel. As the amount of wire increases, the winding radius fluctuates, affecting the winding circumference and leading to measurement errors. While using a driven layer measurement method can avoid multiple turns of wire, it significantly increases the overall size and cost of the sensor. Summary of the Invention

[0006] The purpose of this invention is to provide an automatic compensation pull rope encoder, which controls the wire rope to wind in a single row along a variable diameter spiral trajectory by setting a measuring wheel with a certain winding groove width. At the same time, it combines the use of a tension spring at the rope end to compensate for the error caused by the change in the winding of the wire rope, and together eliminates the winding layering error, thereby solving at least one of the technical problems existing in the above-mentioned background art.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] This invention provides an automatic compensation pull rope encoder, comprising:

[0009] A measuring wheel with a single row of pull rope wound around it, the other end of which is connected to an elastic compensator, which is connected to the target object to be measured.

[0010] One end of the measuring wheel's shaft is connected to a deformation component, and the other end is connected to a rotary encoder; wherein,

[0011] When the target object moves away from the measuring wheel, the elastic compensator pulls the rope, causing the measuring wheel to rotate and the deformation component to deform and store energy. When the target object moves closer to the measuring wheel, the deformation component causes the measuring wheel to rotate in the opposite direction and retract the rope. The rotation of the measuring wheel drives the rotary encoder to rotate, thus achieving distance measurement.

[0012] The elastic force generated by the deformation of the deformable part is equal to the elastic force when the elastic compensation part pulls the rope, which compensates for the error caused by the smaller number of loops of the rope on the measuring wheel.

[0013] Preferably, the elastic coefficient of the deformable part is K1, the diameter of the measuring wheel is D, the diameter of the pull rope is d, the circumference of the pull rope wound on the measuring wheel is C, and the tension on the pull rope is F;

[0014] The change in elastic force of the deformable component is as follows: (The original text appears to be incomplete and contains several grammatical errors. A more accurate translation would require the full context.)

[0015] AF = C * K1;

[0016] By compensating for the error caused by the overlapping of the tension ropes during the measurement process through the deformation of the elastic compensator under stress, the elastic coefficient K2 of the elastic compensator is:

[0017] ΔF=AC*K2

[0018]

[0019] Preferably, the measuring wheel is located inside the housing, and both ends of the rotating shaft can rotatably extend out of the housing and are respectively connected to the deforming component and the rotary encoder.

[0020] Preferably, a guide pulley is rotatably provided inside the housing, and one end of the pull rope extends out of the housing after passing over the guide pulley and is connected to the elastic compensation member.

[0021] Preferably, the deformable element is a planar spiral spring.

[0022] Preferably, a spiral spring box is provided on one side of the outer casing, the planar spiral spring is disposed in the spiral spring box, one end of the planar spiral spring is connected to the rotating shaft, and the other end of the planar spiral spring is connected to the spiral spring box.

[0023] Preferably, the rotary encoder is connected to the housing.

[0024] Preferably, the outer casing is provided with a through hole for the pull rope to extend and connect with the elastic compensation member.

[0025] Preferably, the two ends of the elastic compensation member are respectively connected to a first connector and a second connector, the pull rope is connected to the first connector, and the second connector is connected to the target object to be measured.

[0026] Preferably, the elastic compensating element is a tension spring.

[0027] The beneficial effects of this invention are: by using an automatic compensation method, the stacking error caused by multiple turns of winding in existing draw-wire encoders is reduced; the structure is simple and has almost no impact on the size and manufacturing cost of the sensor, thus significantly compensating for the lack of accuracy of existing draw-wire encoders at a minimal cost.

[0028] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and will become apparent from the description or may be learned by practice of the invention. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a front view structural diagram of the automatic compensation pull rope encoder according to an embodiment of the present invention.

[0031] Figure 2 This is a rear view structural diagram of the automatic compensation pull rope encoder described in an embodiment of the present invention.

[0032] Figure 3 This is a diagram of the internal structure of the automatic compensation pull rope encoder according to an embodiment of the present invention.

[0033] Wherein: 1-pull rope; 2-measuring wheel; 3-elastic compensation component; 5-rotary encoder; 6-housing shell; 7-guide pulley; 8-spring box; 9-through hole; 10-first connector; 11-second connector. Detailed Implementation

[0034] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0035] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0036] It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with their meanings in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as here.

[0037] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, and / or groups thereof.

[0038] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.

[0039] In the description of this specification, 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0040] In the description of this specification, the terms “center,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this technology 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 this technology.

[0041] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of these terms in this art according to the specific circumstances.

[0042] To facilitate understanding of the present invention, the present invention will be further explained and described below with reference to the accompanying drawings and specific embodiments. However, the specific embodiments do not constitute a limitation on the embodiments of the present invention.

[0043] Those skilled in the art should understand that the accompanying drawings are merely schematic diagrams of embodiments, and the components in the drawings are not necessarily essential for implementing the present invention.

[0044] like Figures 1 to 3 As shown, this embodiment provides an automatic compensation pull-cord encoder, comprising: a measuring wheel 2 with a pull cord 1 wound in a single row, the other end of the pull cord 1 connected to an elastic compensation member 3, the elastic compensation member 3 connected to the target object to be measured; one end of the rotating shaft of the measuring wheel 2 connected to a deformation member, and the other end of the rotating shaft of the measuring wheel 2 connected to a rotary encoder 5; wherein, when the target object to be measured moves away from the measuring wheel 2, the elastic compensation member 3 pulls the pull cord 1, causing the measuring wheel 2 to rotate and the deformation member to deform and store energy; when the target object to be measured moves closer to the measuring wheel 2, the deformation member causes the measuring wheel 2 to rotate in the opposite direction to retract the pull cord 1; the rotation of the measuring wheel 2 causes the rotary encoder 5 to rotate, thereby realizing distance measurement. The elastic force generated by the deformation of the deformation member is equal to the elastic force when the elastic compensation member 3 pulls the pull cord, and the elastic compensation member 3 compensates for the error caused by the decrease in the number of loops of the pull cord on the measuring wheel 2.

[0045] In specific embodiments, the pull rope 1 can be a steel wire rope, but in actual applications, under special working conditions, the pull rope can be made of other materials.

[0046] In one specific embodiment, the deformable element is a planar spiral spring, also known as a planar coiled spring. This spring is made of steel strip wound around a spring. A spring can generate a torsional moment in a plane perpendicular to its axis, thereby storing energy. One end of the planar spiral spring is connected to the shaft of the measuring wheel 2, and the other end is fixed. When the pull rope 1 pulls the measuring wheel 2 to rotate, the shaft of the measuring wheel 2 causes the spiral spring to deform and store energy. When the external force on the pull rope 1 disappears, the planar spiral spring releases energy and returns to its original shape, causing the measuring wheel 2 to rotate in the opposite direction and pull back the pull rope 1. Simultaneously, a rotary encoder 5, which rotates coaxially with the measuring wheel 2, completes the distance measurement.

[0047] In this embodiment, the relationship between the elastic coefficients of the deformable part and the elastic compensation part 3 is as follows: Specifically, let the elastic coefficient of the deformable part be K1, the diameter of the measuring wheel 2 be D, the diameter of the pull rope 1 be d, the circumference of the pull rope 1 wound on the measuring wheel 2 be C, and the tension on the pull rope 1 be F.

[0048] Then, for each turn of the rope 1 outward, the change in elastic force of the deformable component is as follows:

[0049] ΔF = C * K1;

[0050] By compensating for the error caused by the overlapping of the rope 1 during the measurement process through the deformation of the elastic compensator 3 under stress, the elastic coefficient K2 of the elastic compensator 3 is:

[0051] ΔF=ΔC*K2

[0052]

[0053] Specifically, the automatic compensation pull rope encoder in this embodiment includes a main housing 6, the measuring wheel 2 is disposed inside the housing 6, and both ends of the rotating shaft can rotatably extend out of the housing 6 and are respectively connected to the deformation component and the rotary encoder 5.

[0054] For example, mounting holes are provided on both side walls of the outer casing 6, and bearings are installed in the mounting holes. The outer ring of the bearing is fixedly connected to the side wall of the outer casing, and the rotating shaft extends out of the outer casing 6 through the inner ring of the bearing. The inner ring of the bearing is fixedly connected to the surface of the rotating shaft, thereby realizing the rotation of the rotating shaft.

[0055] A guide pulley 7 is rotatably installed inside the outer casing 6. One end of the pull rope 1 passes over the guide pulley 7 and extends out of the outer casing 6 to connect with the elastic compensation member 3. The guide pulley 7 facilitates the stable and reliable extension of the pull rope 1 from the outer casing, preventing swaying or loosening during pulling or retraction.

[0056] A spiral spring box 8 is provided on one side of the housing 6. The planar spiral spring is disposed inside the spiral spring box 8. One end of the planar spiral spring is connected to the rotating shaft, and the other end of the planar spiral spring is connected to the spiral spring box 8. The rotary encoder 5 is connected to the housing 6. The housing 6 is provided with a through hole 9 for the pull rope 1 to extend and connect with the elastic compensation member 3.

[0057] The elastic compensation component 3 has a first connector 10 and a second connector 11 connected to its two ends respectively. The pull rope 1 is connected to the first connector 10, and the second connector 11 is connected to the target object to be measured.

[0058] In specific embodiments, the elastic compensation element 3 can be a tension spring, but in practical applications, a miniature hydraulic or pneumatic rod can also be used instead. For example, the two ends of the miniature hydraulic or pneumatic rod are respectively connected to the first connector 10 and the second connector 11.

[0059] In actual operation, the movement or extension of the target to be measured pulls the elastic compensator 3 via the second connector 11. The elastic compensator 3 then pulls the pull rope via the first connector 10, thereby rotating the measuring wheel 2 and ultimately the rotary encoder 5 to achieve distance measurement. Since the grooves of the measuring wheel 2 only accommodate a single row of pull ropes, measurement errors caused by rope stacking and shifting are avoided. This ensures that the pull rope length corresponds to the winding of the planar spiral spring, and the pulled-out length has a linear relationship with the spiral spring force. The smaller the rope loop, the greater the spring force; the larger the rope loop, the smaller the spring force. Because the spiral spring force equals the compensating spring force, the compensating spring experiences increased force, compensating for the error caused by the smaller rope loop.

[0060] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that, based on the technical solutions disclosed in the present invention, various modifications or variations that can be made by those skilled in the art without creative effort should be included within the scope of protection of the present invention.

Claims

1. An automatic compensation pull rope encoder, characterized in that, include: A measuring wheel (2) with a single row of pull rope (1) wound around it, the other end of the pull rope (1) is connected to an elastic compensator (3), and the elastic compensator (3) is connected to the target object to be measured. One end of the shaft of the measuring wheel (2) is connected to a deformation component, and the other end of the shaft of the measuring wheel (2) is connected to a rotary encoder (5); wherein, When the target object to be measured moves away from the measuring wheel (2), the elastic compensation component (3) pulls the rope (1) to drive the measuring wheel (2) to rotate, causing the deformation component to deform and store energy; when the target object to be measured approaches the measuring wheel (2), the deformation component drives the measuring wheel (2) to rotate in the opposite direction to retract the rope (1); the rotation of the measuring wheel (2) drives the rotary encoder (5) to rotate, thus realizing distance measurement; Among them, the elastic force generated by the deformation of the deformable part is equal to the elastic force when the elastic compensator (3) pulls the rope. The elastic compensator (3) compensates for the error caused by the smaller loop of the rope on the measuring wheel (2). Let the elastic modulus of the deformable part be... The diameter of the measuring wheel (2) is D, the diameter of the pull rope (1) is d, the circumference of the pull rope (1) wound on the measuring wheel (2) is C, and the tension on the pull rope (1) is F; Then, for each turn the rope (1) is pulled outward, the change in elastic force of the deformable part is as follows: ； By compensating for the error caused by the overlapping of the rope (1) during the measurement process through the deformation of the elastic compensator (3) under stress, the elastic coefficient of the elastic compensator (3) is determined. for: 。 2. The automatic compensation draw rope encoder according to claim 1, characterized in that, The measuring wheel (2) is located inside the housing (6). Both ends of the rotating shaft can rotatably extend out of the housing (6) and are connected to the deformable component and the rotary encoder (5) respectively.

3. The automatic compensation draw rope encoder according to claim 2, characterized in that, The outer shell (6) is rotatably equipped with a guide pulley (7), and one end of the pull rope (1) extends out of the outer shell (6) after passing over the guide pulley (7) and is connected to the elastic compensation member (3).

4. The automatic compensation draw rope encoder according to claim 3, characterized in that, The deformable component is a planar spiral spring.

5. The automatic compensation draw rope encoder according to claim 4, characterized in that, A spiral spring box (8) is provided on one side of the outer shell (6). The planar spiral spring is located inside the spiral spring box (8). One end of the planar spiral spring is connected to the rotating shaft, and the other end of the planar spiral spring is connected to the spiral spring box (8).

6. The automatic compensation draw rope encoder according to claim 2, characterized in that, The rotary encoder (5) is connected to the housing (6).

7. The automatic compensation draw rope encoder according to claim 2, characterized in that, The outer casing (6) is provided with a through hole (9) for the pull rope (1) to extend and connect with the elastic compensation member (3).

8. The automatic compensation draw rope encoder according to claim 1, characterized in that, The elastic compensation component (3) is connected to a first connector (10) and a second connector (11) at both ends. The pull rope (1) is connected to the first connector (10), and the second connector (11) is connected to the target object to be measured.

9. The automatic compensation draw rope encoder according to claim 8, characterized in that, The elastic compensation component (3) is a tension spring.

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