Pull rope sensor
By using a coiled arrangement of the pull belt in the draw rope sensor and combining elastic elements and sensing elements, the problems of complex structure and low measurement accuracy of the traditional draw rope sensor are solved, and higher displacement measurement accuracy and structural simplification are achieved.
Patent Information
- Application Number
- CN202421317163.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-07
- Publication Date
- 2025-02-14
- Estimated Expiration
- 2034-06-07
AI Technical Summary
Because the traditional pull rope sensor is arranged in a flat winding mode, the structure is complex and the winding is difficult, and it is difficult to ensure the line arrangement accuracy of the pull rope, which in turn affects the measurement accuracy.
The design of a drawstring sensor is adopted, wherein the drawstring is coiled on the rotation shaft in a coiled manner, and the drawstring is coiled by applying a force to retract the drawstring, and the sensing element is used to measure the displacement of the drawstring.
It improves the displacement measurement accuracy of the sensor, simplifies the structure, reduces the difficulty of winding, and realizes a flat product design, suitable for more application scenarios.
Smart Images
Figure CN222481376U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of sensors, and in particular relates to a pull-rope sensor. Background Art
[0002] The draw-wire sensor is a displacement sensor that converts the linear movement of the target element into an electrical signal that can be measured, recorded or transmitted, thereby realizing displacement measurement. In terms of structural composition, the draw-wire sensor includes a rotating shaft and a drawstring that is wound flat on the rotating shaft with equal diameters. The rotating shaft is linked to a potentiometer. After the target element is connected to the free end of the drawstring, the target element moves, and the drawstring can be pulled off the rotating shaft circle by circle. In this process, the amount of movement of the drawstring is linearly related to the angle of the rotating shaft, so the potentiometer linked to the rotating shaft can collect and form a displacement output signal to realize the displacement measurement of the target element.
[0003] In the traditional technology of draw-wire sensors, since the drawstring is arranged on the rotating shaft in an equal-diameter flat winding manner (i.e., spiral winding), extremely precise wiring is required to achieve good linear conversion measurement. Usually, a threaded groove reel is used to prevent wire jamming and wire jumping. This wiring arrangement method is not only complex in structure and difficult to wind, but it is also difficult to ensure that the drawstring has good and stable wire arrangement accuracy, which makes it difficult to improve the measurement accuracy of the sensor. Utility Model Content
[0004] In view of this, the utility model provides a pull-wire sensor, aiming to improve the measurement accuracy of the sensor.
[0005] To achieve the above purpose, the technical solution of the utility model is as follows:
[0006] A pull rope sensor includes a base, and the key points are: a rotating shaft is rotatably installed on the base, and a pull belt is wound on the rotating shaft, an elastic element is installed between the base and the rotating shaft, and the elastic element exerts a force to make the pull belt be wound on the rotating shaft; the pull belt is pulled outward, and the pull belt can overcome the resistance of the elastic element and be pulled outward; a sensor element is installed on the base, and the sensor element is used to measure the displacement of the pull belt when it is pulled outward.
[0007] Preferably, a prestressing device is further included, and the prestressing device can pre-tighten the elastic element manually or electrically.
[0008] Preferably, at least one guide wheel is arranged on the base, and the drawstring is in rolling contact with the side of the guide wheel, and the guide wheel is used to enable the drawstring to be linearly pulled out in a predetermined direction.
[0009] Preferably, the drawstring includes a coiled section and a non-coiled section, the sensing element is a displacement encoder arranged on one side of the non-coiled section, and the drawstring is integrated with a code tape matching the displacement encoder.
[0010] Preferably, the drawstring is a steel belt, and grids are arranged in an array along its length. The grids may be through-hole type or non-through-hole type.
[0011] Preferably, the displacement encoder is a non-contact inductive encoder, and the code band is a grating, an inductive grating or a magnetic grating.
[0012] Preferably, the pull belt includes a coiled section and a non-coiled section, the sensor element is a rotary encoder arranged on one side of the non-coiled section, and the pull belt is a synchronous belt matching the rotary encoder.
[0013] Preferably, there are two rotary encoders, and the rotation diameters of the two rotary encoders are different. Among the two rotary encoders, one is an incremental encoder and the other is an absolute encoder.
[0014] Preferably, the base includes a support plate, the rotating shaft has a first end and a second end respectively passing through both sides of the support plate, the drawstring is coiled on the first end of the rotating shaft, the base is installed with a column on one side corresponding to the second end of the rotating shaft, and the elastic element is a coil spring, one end of which is connected to the second end, and the other end is connected to the mounting column.
[0015] Preferably, a support column is provided on the side of the support plate away from the mounting column, a circuit board is fixedly connected to the support column, the drawstring is coiled between the circuit board and the support plate, the circuit board is integrated with a digital processing circuit, the digital processing circuit includes a posture sensor, and the data of the posture sensor is used to compensate for the error of the drawstring caused by gravity or acceleration.
[0016] Preferably, the rotating shaft is detachably mounted or integrally formed with a winding disk, the draw belt is directly wound on the winding disk, and an annular groove is provided on the outer side of the winding disk, which helps to stably wind the draw belt on the winding disk. During the specific assembly, the rotating shaft rotates relative to the base body, and the winding disk and the rotating shaft are in a fixed sleeve relationship. In addition, the rotating shaft can also be fixedly installed relative to the base body, and the winding disk and the rotating shaft are in a rotational assembly relationship.
[0017] Preferably, the rotating shaft is a hollow structure, and the elastic element is installed in the middle hollow position of the rotating shaft.
[0018] Compared with the prior art, the beneficial effects of the utility model are:
[0019] 1. With the drawstring sensor provided by the utility model, the drawstring is wound on the rotating shaft in a coiled manner with a variable diameter. Whether the drawstring displacement is directly measured by a displacement sensor or measured by an angle sensor, it is unrelated to the rotation amount of the rotating shaft and is only related to the sensor detection system itself. Therefore, compared with the traditional spiral winding method, it has higher displacement measurement accuracy.
[0020] 2. The use of coiling method to roll the pull rope has the technical advantages of simple structure, good reliability, and the ability to eliminate the complex wiring structure. In addition, a flattened sensor product can also be obtained, which can meet more application scenarios and has extremely broad market application prospects. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 Schematic diagram of the structure of the pull rope sensor (pull rope 3 facing upward).
[0022] Figure 2 It is a schematic diagram of the structure of the pull-wire sensor (the elastic element 4 is facing upward).
[0023] Figure 3 Schematic diagram of the decomposed structure of the draw wire sensor.
[0024] Figure 4 Schematic diagram of the first layout of the sensor elements in the rope sensor.
[0025] Figure 5 Schematic diagram of the second layout of the sensor elements in the rope sensor. DETAILED DESCRIPTION
[0026] The utility model is further described below in conjunction with embodiments and drawings.
[0027] like Figure 1 and 3 As shown, a drawstring sensor comprises a base 1, a rotating shaft 2 is rotatably mounted in the middle of the base 1, a drawstring 3 is connected to the rotating shaft 2, and the drawstring 3 is wound around the rotating shaft 2 in a coiled manner with the inner end of the drawstring 3 as the starting point, and the outer end of the drawstring 3 extends to the outside of the base 1 for connecting to the target component to be tested. Figure 2 It can be seen that an elastic element 4 is installed between the base 1 and the rotating shaft 2. In this embodiment, the elastic element 4 is a coil spring, which exerts a force to make the drawstring 3 roll up on the rotating shaft 2. Pulling the drawstring 3 outward can drive the rotating shaft 2 to rotate to overcome the resistance of the elastic element 4, so that the drawstring 3 can be pulled outward. A sensor element is installed on the base 1, and the sensor element is used to measure the displacement of the drawstring 3 when it is pulled outward.
[0028] When measuring the linear displacement of the target element, the target element is connected to the outer end of the drawstring 3. The target element moves to drag the drawstring 3 and pull out the drawstring 3 wound on the shaft 2. At this time, the displacement of the drawstring 3 recognized by the sensor element represents the linear displacement of the target element, realizing displacement sensing detection. Figure 3The pull belt 3 is wound on the rotating shaft 2 in a coiled manner. During the measurement of the linear displacement of the target element, the output signal is not detected by the rotating shaft of the coil, but by the sensor element before the pull belt 3 extends from the substrate 1. Compared with the existing linear conversion measurement, it has higher measurement accuracy. At the same time, this winding method has a simple structure, good reliability, and eliminates the complex wiring structure. In addition, a flat product can also be obtained to meet more application scenarios.
[0029] Based on the above structure, this embodiment provides two layout modes of sensor elements, as follows:
[0030] Layout method 1
[0031] Please refer to the attached Figure 4 The entire drawstring 3 is divided into a coiled section 3a and a non-coiled section 3b. The sensing element is a displacement encoder 6 arranged on one side of the non-coiled section 3b of the drawstring 3. The drawstring 3 is integrated with a code tape that matches the displacement encoder 6. During the pulling process of the drawstring 3, the displacement encoder 6 interacts with the code tape to directly complete the displacement measurement. In specific applications, the displacement encoder 6 can be an inductive encoder, and the code tape can be a grating, an inductive grating, or a magnetic grating.
[0032] One implementation of the inductor grid is that the pull belt 3 is made of a steel belt, and the steel belt is punched with holes in an array in the length direction, and each hole can form a high-precision inductor grid and output a high-precision signal. Based on this, a thinner flexible steel belt can be used, so that the number of winding layers is greatly increased, thereby improving the range.
[0033] In the first sensor element layout method, at least one guide wheel 7 can be installed on the base 1, and the non-coiled section 3b of the pull belt 3 is in rolling contact with the side of the guide wheel 7, so as to ensure that the pull belt 3 can be pulled out linearly in a predetermined direction, thereby improving the matching accuracy between the displacement encoder 6 and the code belt.
[0034] Layout method 2
[0035] Please refer to the attached Figure 5, in the whole drawstring 3, it is divided into a coiling section 3a and a non-coiling section 3b. The coiling section 3a is responsible for winding on the rotating shaft 2. The sensing element is a rotary encoder 8 arranged on one side of the non-coiling section 3b. The whole drawstring 3 is constructed as a synchronous belt linked with the rotary encoder 8. When the synchronous belt moves, it can drive the measuring wheel of the rotary encoder 8 to rotate. The movement of the drawstring 3 and the rotation angle of the rotary encoder 8 are linearly related, so the linear displacement of the drawstring 3 can be obtained by angle conversion. In this structural layout, the movement of the measuring wheel of the rotary encoder 8 is not affected by the winding accuracy of the coiling section 3a of the drawstring 3, so it has obvious advantages over the measurement method described in the background technology. In addition, the rotary encoder 8 can use a magnetic encoder. The synchronous belt has many excellent mechanical parameter advantages and is a commonly used mature accessory in industry. In addition, the accuracy of this solution is only related to the synchronous belt and the detection system, and has nothing to do with the winding shaft, so it has a significant accuracy advantage.
[0036] Furthermore, two rotary encoders 8 may be arranged inside the non-coiled section 3b, each rotary encoder 8 having a different rotation diameter and a different circumference, which together constitute differential length detection. Of the two rotary encoders 8, the one close to the outer end of the drawstring 3 is an incremental encoder, and the other is an absolute encoder, so as to realize multi-turn absolute value calculation and improve measurement accuracy.
[0037] In the second sensor element layout mode, a limiter 9 may be installed at the position where the drawstring 3 extends out of the base 1 to ensure that the drawstring 3 can be pulled out or retracted more stably.
[0038] In this embodiment, the drawstring sensor is provided with a prestressing device, which can pre-tighten the elastic element 4 manually or electrically to maintain a constant tension of the drawstring 3 and improve the measurement accuracy.
[0039] For example Figure 1 and 2 As shown, the base 1 includes a support plate 1a, the rotating shaft 2 has a first end a and a second end b respectively passing through both sides of the supporting plate 1a, the pull belt 3 is coiled on the first end a of the rotating shaft 2, the base 1 is installed with a column 1b on the side corresponding to the second end b, and the elastic element 4 is a coil spring, one end of which is connected to the second end b, and the other end is connected to the installation column 1b.
[0040] In this embodiment, the coil spring is installed at one end of the rotating shaft 2, and the two are coaxially sleeved. In addition, the coil spring can also be coaxially sleeved in the middle of the rotating shaft 2, or installed in other ways of coaxiality. For example: the coaxial installation method in the middle of the rotating shaft 2 can be that the rotating shaft 2 is constructed as a hollow structure, and the elastic element 4 is a coil spring, which is installed in the middle hollow position of the rotating shaft 2.
[0041] Of course, other elements besides the winding spring may also be used to provide the elastic winding force, such as a torsion spring, a tension spring, a leaf spring, a plate spring, etc.
[0042] A support column 1c is provided on one side of the support plate 1a away from the mounting column 1b, a circuit board 5 is fixedly connected to the support column 1c, and the pull belt 3 is coiled between the circuit board 5 and the support plate 1a. Such a design not only facilitates product assembly, but also helps to form a thin product.
[0043] Furthermore, a digital processing circuit is integrated in the circuit board 5, and the digital processing circuit is used to compensate for the error caused by the bending of the drawstring 3 due to gravity. In addition, a winding diameter measuring device can be set in the drawstring sensor, and combined with an encoder, the pull-out length can be converted.
[0044] Finally, it should be noted that the above description is only a preferred embodiment of the present invention. Under the guidance of the present invention, ordinary technicians in this field can make a variety of similar expressions without violating the purpose and claims of the present invention, and such changes fall within the scope of protection of the present invention.
Claims
1. A draw wire sensor, comprising a substrate (1), characterized in that: A rotating shaft (2) is rotatably mounted on the base (1), a drawstring (3) is wound around the rotating shaft (2), an elastic element (4) is mounted between the base (1) and the rotating shaft (2), and the elastic element (4) exerts a force that causes the drawstring (3) to be wound around the rotating shaft (2); The drawstring (3) is pulled outward, and the drawstring (3) can overcome the resistance of the elastic element (4) and be pulled outward; a sensor element is installed on the base (1), and the sensor element is used to measure the displacement of the drawstring (3) when it is pulled outward.
2. The draw wire sensor according to claim 1, characterized in that: It also comprises a prestressing device, which can prestress the elastic element (4) manually or electrically.
3. The draw wire sensor according to claim 1, characterized in that: At least one guide wheel is arranged on the base (1), and the drawstring (3) is in rolling contact with the side of the guide wheel. The guide wheel is used to enable the drawstring (3) to be linearly pulled out in a predetermined direction.
4. The draw wire sensor according to claim 1, characterized in that: The drawstring (3) comprises a coiled section (3a) and a non-coiled section (3b); the sensing element is a displacement encoder arranged on one side of the non-coiled section (3b); and the drawstring (3) is integrated with a code belt matching the displacement encoder.
5. The draw wire sensor according to claim 4, characterized in that: The drawstring (3) is a steel belt, and grids are arranged in an array in the length direction thereof.
6. The draw wire sensor according to claim 4, characterized in that: The displacement encoder is a non-contact inductive encoder, and the code band is a grating, an inductive grating or a magnetic grating.
7. The draw wire sensor according to claim 1, characterized in that: The pull belt (3) comprises a coiled section (3a) and a non-coiled section (3b); the sensor element is a rotary encoder arranged on one side of the non-coiled section (3b); and the pull belt (3) is a synchronous belt matching the rotary encoder.
8. The draw wire sensor according to claim 7, characterized in that: There are two rotary encoders, and each rotary encoder has a different rotation diameter.
9. The draw wire sensor according to claim 8, characterized in that: Among the two rotary encoders, one is an incremental encoder and the other is an absolute encoder.
10. The draw wire sensor according to claim 1, characterized in that: The base (1) includes a support plate (1a), the rotating shaft (2) has a first end (a) and a second end (b) respectively passing through the two sides of the support plate (1a), the pull belt (3) is coiled on the first end (a) of the rotating shaft (2), the base (1) is installed with a column (1b) on one side corresponding to the second end (b) of the rotating shaft (2), and the elastic element (4) is a coil spring, one end of which is connected to the second end (b) and the other end is connected to the installation column (1b).
11. The draw wire sensor according to claim 10, characterized in that: A support column (1c) is provided on one side of the support plate (1a) away from the mounting column (1b), a circuit board (5) is fixedly connected to the support column (1c), the drawstring (3) is coiled between the circuit board (5) and the support plate (1a), the circuit board (5) is integrated with a digital processing circuit, the digital processing circuit includes a posture sensor, and data from the posture sensor is used to compensate for errors of the drawstring (3) caused by gravity or acceleration.
12. The draw wire sensor according to claim 1, characterized in that: The rotating shaft (2) is detachably mounted with or integrally formed with a winding disk, and an annular groove is provided on the outer side of the winding disk for winding the drawstring (3).
13. The draw wire sensor according to claim 1, characterized in that: The rotating shaft (2) is a hollow structure, and the elastic element (4) is installed in the middle hollow position of the rotating shaft (2).