A device and method for maintaining tension constant during holding and clamping of a vibrating string

Abstract

The present application provides a device and method for keeping the tension of a vibrating string unchanged during clamping and fixing, which comprises a strain tube with a string clamping device, a pressing plate, a guide block and a pressure mechanism. The string clamping device is fixed on the guide block by the pressing plate, so that the position of the string clamping device is kept relatively unchanged. The pressure mechanism is arranged opposite to the top block in the guide block, so that the string clamping device is simultaneously deformed towards the central axis by the pressure from the pressure mechanism. The position of the center of the string clamping device does not change, so that the tension of the vibrating string does not change before and after the two ends of the vibrating string are fixed. The tension stability of the vibrating string during clamping and fixing is maintained. In addition, the constant tension applied to the vibrating string by the tension providing mechanism can further improve the production consistency of the initial state of the vibrating string sensor.

Description

Technical Field

[0001] The present invention relates to the technical field of vibrating wire sensors, and in particular to a device and method for maintaining constant tension of a vibrating wire during a clamping and fixing process. Background Art

[0002] The vibrating string sensor is a resonant sensor that uses a taut metal string as the sensitive element. It outputs a frequency signal, does not require A / D or D / A conversion, has strong anti-interference ability, and can be transmitted over long distances. Due to its advantages such as good stability, good repeatability, simple structure, long life and high sensitivity, it is widely used in dams, bridges, roads, etc. to detect force, displacement and cracks.

[0003] A common method for fixing a vibrating string is to pass the vibrating string through two string clamps and use external force to deform the string clamps, thereby clamping the vibrating string. However, the traditional method of applying external force is to apply pressure in a single direction to the string clamps. During the pressure application process, the string clamps will deform in a single direction, and after the deformation, the center position of the string clamps will change relative to the main structure, resulting in changes in the length of the clamped vibrating string and the axial tension relative to before clamping and fixing, affecting the initial state performance of the vibrating string sensor. Summary of the Invention

[0004] Based on this, the present invention proposes a device and method for maintaining constant tension of a vibrating wire during clamping and fixing, aiming to solve the problem in the prior art that the tension of the vibrating wire varies greatly during clamping and fixing.

[0005] According to a first aspect of an embodiment of the present invention, there is provided an apparatus for maintaining constant tension in a vibrating wire during clamping and fixing, the apparatus comprising a base, a tension-providing mechanism movably connected to the base, a limiting mechanism fixed to the base, and a pressure mechanism disposed above the limiting mechanism. The limiting mechanism comprises a slot fixed to the base, and a guide block adapted to fit the slot. The guide block defines a guide slot for accommodating a top block adapted to fit the guide slot. A pressure plate is disposed above the guide block for securing a strain gauge to the guide block. The strain gauge is configured to wrap around the vibrating wire and a string clamp disposed at both ends of the vibrating wire. An end of the vibrating wire proximate the tension-providing mechanism is configured to connect to the tension-providing mechanism, and the tension-providing mechanism is disposed in the direction in which the vibrating wire extends. The tension-providing mechanism is configured to provide a preset tension to the vibrating wire. The pressure mechanism is located above the string clamp of the vibrating wire and in the same direction as the top block. When the vibrating wire is fixed to the guide block, the pressure mechanism applies pressure to the string clamp to cause the clamp to deform.

[0006] Furthermore, a first air guide hole is provided on the base, and a second air guide hole matching the first air guide hole is provided on the trough body.

[0007] Furthermore, the guide block has an end close to the tension providing mechanism that extends a first limiting portion away from the base, and the limiting portion is provided with a first through hole, which corresponds to the tube mouth of the strain tube, and the first through hole is used to pass the vibrating string into the string clamp.

[0008] Furthermore, a second limiting portion is extended from one end of the guide block away from the tension providing mechanism in a direction away from the base, and the first limiting portion and the second limiting portion are used for the two ends of the strain tube to respectively abut against the first limiting portion and the second limiting portion when the strain tube is placed on the guide block.

[0009] Furthermore, the length of the top block is greater than the depth of the guide groove.

[0010] Furthermore, a second through hole is provided on the pressure plate, and an internal threaded hole matching the second through hole is provided on the guide block. The strain tube is fixed to the guide block by passing a screw through the second through hole and rotating it into the internal threaded hole.

[0011] Furthermore, when the strain tube is fixed to the guide block through the pressing plate and the guide block is placed in the slot body, the strain tube abuts against the top block, and a preset gap is left between the guide block and the slot bottom.

[0012] Furthermore, the pressure mechanism includes a press and a pressure head extending from the press toward the top block, and the shape of the pressure head is the same as that of the top block.

[0013] Furthermore, the tension providing mechanism includes a string clamping assembly, a pulley, a counterweight, and a pull rope connecting the string clamping assembly and the counterweight through the pulley, wherein the string clamping assembly includes a vibrating string fixing part and a slider fixedly connected to the vibrating string fixing part, and the slider cooperates with a slide rail installed on the base to enable the string clamping assembly to slide on the base.

[0014] A second aspect of an embodiment of the present invention provides a method for maintaining a constant tension in a vibrating wire during clamping and fixing, which is applied to the above-mentioned device for maintaining a constant tension in a vibrating wire during clamping and fixing. The method comprises:

[0015] Place the guide block into the slot, then install the top block into the guide slot in the guide block, then place the strain gauge tube with string clamps installed at both ends on the guide block, and fix the strain gauge tube to the guide block using a pressure plate;

[0016] Passing the vibrating string through the string clamp, moving the pressure mechanism to an upper portion of the string clamp away from the tension providing mechanism, and controlling the pressure mechanism to press downward to secure the string clamp to the vibrating string;

[0017] The end of the vibrating string close to the tension providing mechanism is fixedly connected to the tension providing mechanism, and a fixed tension is applied to the vibrating string under the traction of the tension providing mechanism. The pressure mechanism is then moved to above the string clamp close to one end of the tension providing mechanism, and the pressure mechanism is controlled to press downward.

[0018] Compared with the existing technology: by fixing the strain tube with the string clamp on the guide block through the pressure plate, the position of the string clamp can be kept relatively stationary. Since the top block arranged in the guide block is arranged relative to the pressure mechanism, pressure is applied to the string clamp from top to bottom at the same time, causing the string clamp to deform toward the central axis at the same time, and the position of the center of the string clamp does not change relatively. Therefore, the tension on the vibrating string does not change before and after the vibrating string is fixed at both ends, thereby maintaining the tension stability of the vibrating string during the clamping and fixing process. In addition, the constant tension applied to the vibrating string by the tension providing mechanism can further improve the production consistency of the initial state of the vibrating string sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the structure of the device for maintaining constant tension during the clamping and fixing process of the vibrating wire in the first embodiment of the present invention;

[0020] Figure 2 Flowchart of a method for maintaining constant tension during clamping and fixing of a vibrating wire according to a second embodiment of the present invention.

[0021] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0022] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the accompanying drawings. The drawings illustrate several embodiments of the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present invention.

[0023] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0025] Example 1

[0026] See also Figure 1 , shown is a device for maintaining constant tension in a vibrating wire during clamping and fixing in a first embodiment of the present invention, comprising a base 1, a tension providing mechanism movably connected to the base 1, a limiting mechanism fixed to the base 1, and a pressure mechanism disposed above the limiting mechanism, wherein:

[0027] The base 1 can be fixed to the workbench by screwing. When the base 1 is fixed, the limiting mechanism is fixed on the base 1, wherein the limiting mechanism can also be fixed to the base 1 by screwing. Specifically, the limiting mechanism includes a slot body 2 fixed on the base 1, and a guide block 3 adapted to the slot body 2. It can be understood that the guide block 3 can be just placed in the slot body 2 and fit into the groove of the slot body 2. Since the guide block 3 is limited by the slot body 2, the slot body 2 can limit the remaining degrees of freedom of the guide block 3 except the pressurizing direction, that is, the guide block 3 can only move in the vertical direction of the slot body 2. In addition, a guide groove is provided in the guide block 3, which is used to accommodate the top block 6 adapted to the guide groove, that is, the movement of the top block 6 is limited by the guide groove and can only move in the vertical direction of the guide groove. It is noted that when the strain tube 4 is placed on the guide block 3, the string clamp 41 in the strain tube 4 should be directly above the top block 6, and the length of the top block 6 should be greater than the depth of the guide groove, that is, when the guide block 3 and the top block 6 are placed in the groove body 2, and the guide block 3 and the top block 6 both touch the bottom of the groove body 2, the top block 6 is higher than the guide block 3. In this embodiment, when the strain tube 4 is fixed to the guide block 3 by the pressure plate 5, and the guide block 3 is placed in the groove body 2, the strain tube 4 and the top block 6 are abutted, and a preset gap is left between the guide block 3 and the bottom of the groove. The preset gap is the height of the top block 6 higher than the guide block 3. In addition, since there are two string clamps 41 in the strain tube 4, and they are located at both ends of the strain tube 4, in order to cooperate with the string clamps 41, the guide grooves are also symmetrically arranged on both sides of the guide block 3, and match the positions of the string clamps 41.

[0028] Specifically, a pressure plate 5 is provided above the guide block 3, and the pressure plate 5 is used to fix the strain tube 4 on the guide block 3, wherein a second through hole is provided on the pressure plate 5, and an internal threaded hole matching the second through hole is provided on the guide block 3. The strain tube 4 is fixed to the guide block 3 by passing a screw through the second through hole and rotating it into the internal threaded hole. In this embodiment, a first limiting portion 31 is extended away from the base 1 at one end of the guide block 3 close to the tension providing mechanism, and a first through hole is provided on the limiting portion, and the first through hole corresponds to the tube mouth of the strain tube 4. The first through hole is used to pass the vibrating wire 42 into the string clamp 41. In addition, a second limiting portion 32 is extended away from the base 1 at one end of the guide block 3 away from the tension providing mechanism. The first limiting portion 31 and the second limiting portion 32 is used when the strain tube 4 is placed on the guide block 3, and the two ends of the strain tube 4 respectively abut against the first limiting part 31 and the second limiting part 32. It can be understood that the first limiting part 31, the second limiting part 32 and the guide block 3 form a groove structure. The distance between the first limiting part 31 and the second limiting part 32 is the length of the strain tube 4, that is, the groove structure can accommodate the strain tube 4 and play a limiting role, effectively improving the placement time of the strain tube 4. In addition, when the strain tube 4 is placed, since the first through hole of the first limiting part 31 corresponds to the tube mouth of the strain tube 4, the vibrating string 42 can be inserted into the string clamp 41 of the strain tube 4 through the first through hole until the vibrating string 42 abuts against the second limiting part 32, which can effectively improve the efficiency of the vibrating string 42 passing through the string clamp 41.

[0029] It should be noted that the end of the vibrating string 42 close to the tension providing mechanism is used to connect with the tension providing mechanism, and the tension providing mechanism is arranged in the extension direction of the vibrating string 42. The tension providing mechanism is used to provide a preset tension to the vibrating string 42. Specifically, the tension providing mechanism includes a string clamping assembly, a pulley 85, a counterweight 86, and a pull rope 84 connecting the string clamping assembly and the counterweight 86 through the pulley 85. The string clamping assembly includes a vibrating string fixing member 81 and a slider 82 fixedly connected to the vibrating string fixing member 81. The slider 82 cooperates with a slide rail 83 installed on the base 1 to make the vibrating string 42 have a preset tension. The string clamping assembly slides on the base 1. In this embodiment, the slide rail 83 is fixed to the base 1 by screwing, which can be used to locate the direction of the string. A fixed pulley 85 is installed on the side away from the limiting mechanism. The fixed pulley 85 can be a V-shaped wheel, which can be used to convert the force direction of the vibrating string 42. The two ends of the pull rope 84 are respectively connected to the vibrating string 42 fixing part and the counterweight 86. It can be understood that the weight of the counterweight 86 is used to apply a fixed tension to the vibrating string 42, that is, the modulated counterweight 86 can replace the dynamometer or other manual force measurement and tensioning methods to apply a fixed design tension to both ends of the vibrating string 42.

[0030] Furthermore, the pressure mechanism is located above the string clamp 41 of the vibrating string 42 and is located in the same direction as the top block 6. When the vibrating string 42 is fixed to the guide block 3, the pressure mechanism applies pressure to the string clamp 41 to deform the string clamp 41, thereby clamping and fixing the vibrating string 42. Specifically, the pressure mechanism includes a press 71 and a pressure head 72 extending from the press 71 toward the top block 6, and the shape of the pressure head 72 is the same as that of the top block 6. In this embodiment, the pressure head 72 and the top block 6 can be rectangular parallelepipeds, that is, the area acting on the string clamp 41 is the same, so as to ensure that the pressure is uniform when the pressure acts on the string clamp 41. It can be understood that the pressure head 7 2 When pressure is applied to the string clamp 41 in a single direction, the top block 6 will generate a reaction force of equal magnitude, forming a two-way pressure effect on the string clamp 41, solving the problem of large changes in the tension of the vibrating string 42 during the clamping and fixing process. In addition, a first air guide hole 11 is provided on the base 1, and a second air guide hole 21 matching the first air guide hole 11 is provided on the slot body 2. The purpose of providing the air guide hole is to prevent the guide block 3 from being unable to be pulled out due to negative pressure after being pressed into the slot body 2. To this end, the air between the guide block 3 and the slot body 2 is discharged, which can facilitate the removal of the guide block 3 from the slot body 2. It should be noted that corresponding holes are also required on the workbench for exhaust.

[0031] In this embodiment, a receiving groove 33 is provided in the middle area of ​​the guide block 3. The receiving groove 33 is used to accommodate the coil, and the receiving groove 33 is located below the vibrating wire 42. The coil can be used to detect whether the vibrating wire 42 product is qualified.

[0032] In summary, the device for maintaining constant tension in a vibrating wire during clamping and fixing in the above-mentioned embodiment of the present invention, by fixing the strain tube with the string clamp on the guide block via a pressure plate, can keep the string clamp in a relatively fixed position. Furthermore, because the top block disposed in the guide block and the pressure mechanism are arranged relative to each other, they simultaneously apply pressure to the string clamp from top to bottom, causing the string clamp to deform toward the central axis simultaneously, and the position of the center of the string clamp does not change relative to each other. Therefore, the tension on the vibrating wire does not change before and after the two ends are fixed, thereby maintaining the tension stability of the vibrating wire during the clamping and fixing process. In addition, the constant tension applied to the vibrating wire by the tension providing mechanism can further improve the production consistency of the initial state of the vibrating wire sensor.

[0033] Example 2

[0034] See also Figure 2 , which shows a method for maintaining constant tension during the clamping and fixing process of a vibrating wire in a second embodiment of the present invention, and the method specifically includes steps S21 to S23.

[0035] Step S21: Place the guide block into the slot, then install the top block into the guide slot in the guide block, then place the strain gauge with string clamps installed at both ends on the guide block, and fix the strain gauge to the guide block through a pressure plate.

[0036] After the vibrating wire and the strain tube are fixed to the guide block, since there is no stamping deformation at both ends of the strain tube, the strain tube will be supported on the top blocks at both ends. Since the wire block and the strain tube are fixed as one, the bottom surface of the guide block will be separated from the bottom of the slot body and will not contact. The distance between them is the size of the stamping deformation of the strain tube.

[0037] Step S22: Pass the vibrating string through the string clamp, move the pressure mechanism to the top of the string clamp away from the tension providing mechanism, and control the pressure mechanism to press down to fix the string clamp and the vibrating string.

[0038] Step S23: fix the end of the vibrating string close to the tension providing mechanism to the tension providing mechanism, apply a fixed tension to the vibrating string under the traction of the tension providing mechanism, and then move the pressure mechanism to the top of the string clamp close to one end of the tension providing mechanism, and control the pressure mechanism to press downward.

[0039] Specifically, when the pressure head presses downward, the positions of the top blocks at both ends remain unchanged, and the strain tube and guide block shift downward together with the deformation of the strain tube. During this process, the axis of the strain tube always remains relatively stationary with the guide block, which can effectively solve the problem of large changes in the tension of the vibrating wire during the clamping and fixing process, thereby improving the production consistency of the initial state of the vibrating string sensor.

[0040] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0041] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A device for maintaining constant tension during the clamping and fixing process of a vibrating wire, characterized in that: The invention also provides a method for fixing the tensioning device to the guide block, wherein the pressure mechanism is configured to fix the tensioning device to the guide block, the pressure mechanism being configured to fix the tensioning device to the guide block, the pressure mechanism being configured to fix the tensioning device to the guide block, the pressure mechanism being configured to fix the tensioning device to the guide block, the pressure mechanism being configured to fix the tensioning device to the guide block, the pressure mechanism being configured to fix the tensioning device to the guide block, the pressure mechanism being configured to fix the tensioning device to the guide block, the pressure mechanism being configured to fix the tensioning device to the guide block, the pressure mechanism being configured to fix the tensioning device to the guide block, the pressure mechanism being configured to fix the tensioning device to the guide block, the pressure mechanism being configured to fix the tensioning device to the guide block, the pressure mechanism being configured to fix the tensioning device to the guide block, the pressure mechanism being configured to fix the tensioning device to the guide block, the pressure mechanism being configured to fix the tensioning device to the guide block, the pressure mechanism being configured to fix the tensioning device to the guide block, the pressure mechanism being configured to fix the tensioning device to the When the strain tube is fixed to the guide block through the pressing plate and the guide block is placed in the slot body, the strain tube abuts against the top block, and a preset gap is left between the guide block and the slot bottom.

2. The device for maintaining constant tension during clamping and fixing of a vibrating wire according to claim 1, characterized in that: The base is provided with a first air guide hole, and the tank body is provided with a second air guide hole matching the first air guide hole.

3. The device for maintaining constant tension during clamping and fixing of a vibrating wire according to claim 1, characterized in that: The guide block has an end close to the tension providing mechanism that extends a first limiting portion away from the base, and the limiting portion is provided with a first through hole, which corresponds to the tube mouth of the strain tube, and is used to pass the vibrating string into the string clamp.

4. The device for maintaining constant tension during clamping and fixing of a vibrating wire according to claim 3, characterized in that: A second limiting portion is extended from one end of the guide block away from the tension providing mechanism in a direction away from the base. The first limiting portion and the second limiting portion are used for allowing the two ends of the strain tube to respectively abut against the first limiting portion and the second limiting portion when the strain tube is placed on the guide block.

5. The device for maintaining constant tension during clamping and fixing of a vibrating wire according to claim 1, characterized in that: The length of the top block is greater than the depth of the guide groove.

6. The device for maintaining constant tension during clamping of a vibrating wire according to claim 1, characterized in that: A second through hole is formed on the pressure plate, and an internal threaded hole matching the second through hole is formed on the guide block. The strain tube is fixed to the guide block by a screw passing through the second through hole and rotatingly inserted into the internal threaded hole.

7. The device for maintaining constant tension during clamping and fixing of a vibrating wire according to claim 1, characterized in that: The pressure mechanism includes a press and a pressure head extending from the press toward the top block, and the shape of the pressure head is the same as that of the top block.

8. The device for maintaining constant tension during clamping of a vibrating wire according to claim 1, characterized in that: The tension providing mechanism includes a string clamping assembly, a pulley, a counterweight, and a pull rope connecting the string clamping assembly and the counterweight through the pulley, wherein the string clamping assembly includes a vibrating string fixing part and a slider fixedly connected to the vibrating string fixing part, and the slider cooperates with a slide rail installed on the base to enable the string clamping assembly to slide on the base.

9. A method for maintaining constant tension during the clamping and fixing process of a vibrating wire, characterized in that: Applied to the device for maintaining constant tension during clamping and fixing of a vibrating wire as described in any one of claims 1 to 8, the method comprises: Place the guide block into the slot, then install the top block into the guide slot in the guide block, then place the strain gauge tube with string clamps installed at both ends on the guide block, and fix the strain gauge tube to the guide block using a pressure plate; Passing the vibrating string through the string clamp, moving the pressure mechanism to an upper portion of the string clamp away from the tension providing mechanism, and controlling the pressure mechanism to press downward to secure the string clamp to the vibrating string; The end of the vibrating string close to the tension providing mechanism is fixedly connected to the tension providing mechanism, and a fixed tension is applied to the vibrating string under the traction of the tension providing mechanism. The pressure mechanism is then moved to above the string clamp close to one end of the tension providing mechanism, and the pressure mechanism is controlled to press downward.

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