An elastic body strain structure for load sensor

Abstract

The present application relates to an elastic body strain structure for a load sensor, including: a first fixing seat, a second fixing seat and a strain column; the first fixing seat and the second fixing seat are respectively located at the two ends of the strain column; the strain column is an I-beam structure, the strain column includes a web and two flange plates, the opposite ends of the web are respectively connected to the first fixing seat and the second fixing seat, and the opposite ends of the flange plates are respectively connected to the first fixing seat and the second fixing seat. The present application designs the strain column as an I-beam structure, which greatly improves its ability to resist eccentric loads and restrains the local deformation generated in the area where the upper end face is subjected to concentrated force. Because of the characteristics of the I-beam structure itself, the unbalanced stress will be redistributed, the web will generate considerable tension and hinder the increase of deflection, so that the overall force of the strain column is more reasonable and balanced, thereby improving the anti-eccentric load capacity of the designed load sensor.

Description

Technical Field

[0001] The present application relates to the technical field of load sensors, and in particular to an elastic body strain structure for load sensors. Background Art

[0002] A column sensor is a measuring element. During the measurement process, pressure acts on the elastic body to cause deformation. This strain (positive or negative) is converted into an electronic signal by the strain gauge attached to the elastic body, thereby realizing the measurement of the so-called load.

[0003] However, the elastic strain area of ​​the existing columnar sensors is mostly a columnar structure with a rectangular cross section. This structure has good axial stiffness, but poor radial stiffness, which results in poor anti-eccentric load capacity of the columnar sensors. Secondly, the existing I-beam sensors use a single column as support, which can neither provide a reference for the design method of the three-component force sensor nor improve the lateral range.

[0004] Therefore, how to improve the anti-eccentric load capability of the column sensor has become an urgent problem to be solved by those skilled in the art. Summary of the invention

[0005] In view of this, the present application proposes an elastic body strain structure for a load sensor.

[0006] According to one aspect of the present application, there is provided an elastic body strain structure for a load sensor, which is suitable for the design and processing of a large-range, three-component load sensor, and undergoes elastic deformation under pressure, and comprises: a first fixing seat, a second fixing seat and a strain column;

[0007] The first fixing seat and the second fixing seat are respectively located at two ends of the strain column;

[0008] The strain column is an I-beam structure, and includes a web and two flange plates, wherein opposite ends of the web are respectively connected to the first fixing seat and the second fixing seat, and opposite ends of the flange plates are respectively connected to the first fixing seat and the second fixing seat.

[0009] In a possible implementation manner, there are two or more strain columns, and the two or more strain columns are arranged in a quadrilateral.

[0010] In a possible implementation, the first fixing seat is provided with a first connecting portion and a first fixing portion, and the second fixing seat is provided with a second connecting portion and a second fixing portion;

[0011] The first connection portion and the second connection portion are respectively connected to two ends of the strain column;

[0012] The first fixing portion and the strain column are respectively located at two opposite sides of the first connecting portion;

[0013] The second fixing portion and the strain column are respectively located at two opposite sides of the second connecting portion.

[0014] In a possible implementation, the first connection portion and the second connection portion are both cylindrical structures, and two ends of the strain column are respectively connected to an end surface of the first connection portion and an end surface of the second connection portion;

[0015] The first fixing portion and the second fixing portion are both rectangular structures, the first connecting portion is located in the middle of one side of the first fixing portion, and the second connecting portion is located in the middle of one side of the second fixing portion.

[0016] In a possible implementation manner, the first fixing portion and the second fixing portion are each provided with more than two mounting holes.

[0017] In a possible implementation, there are four strain columns, which are arranged in an equilateral rectangle, and are respectively located at four corners of the equilateral rectangle.

[0018] In a possible implementation manner, the four strain columns are respectively close to the end surface edges of the first connecting portion.

[0019] In a possible implementation, the main body of the strain column is a columnar structure, and buffer grooves are respectively formed on two opposite side surfaces of the strain column.

[0020] In a possible implementation, the main body of the strain column is a rectangular column structure, the two buffer grooves provided on opposite sides of the strain column are both oblong hole structures, and the length direction of the buffer groove is the same as the axial direction of the strain column.

[0021] In a possible implementation manner, the webs of two or more strain columns are arranged parallel to each other.

[0022] This application is applicable to the design and processing of a large-range, three-component load sensor. The first fixing seat and the second fixing seat are respectively connected to the device to be tested, and are used to bear the pressure to be tested. The strain column undergoes elastic deformation under the pressure. Compared with the traditional strain column with a rectangular columnar structure in cross section, this application designs the strain column as an I-beam structure, which greatly improves its ability to resist eccentric loads and restrains the local deformation produced in the area where the upper end face is subjected to concentrated force. Because of the characteristics of the I-beam structure itself, the unbalanced stress will be redistributed, the web will produce considerable tension and delay the development of deflection, making the overall force of the strain column more reasonable and balanced, thereby improving the anti-eccentric load capacity of the adapted sensor.

[0023] Other features and aspects of the present application will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the present application and, together with the description, serve to explain the principles of the present application.

[0025] Figure 1 A design diagram of an elastic body strain structure for a load sensor according to an embodiment of the present application is shown;

[0026] Figure 2 An isometric cross-sectional view showing an elastic body strain structure design for a load sensor according to an embodiment of the present application;

[0027] Figure 3 A front view showing the design of an elastic body strain structure for a load sensor according to an embodiment of the present application;

[0028] Figure 4 A cross-sectional view showing an elastic body strain structure design for a load sensor according to an embodiment of the present application;

[0029] Figure 5 An enlarged cross-sectional view of a strain column of an elastic body strain structure design for a load sensor according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0030] Figure 1 The main structure diagram of the elastic body strain structure for the load sensor according to the embodiment of the present application is shown. Figure 2 An isometric cross-sectional view of an elastic body strain structure design for a load sensor according to an embodiment of the present application is shown. Figure 1 and Figure 2 As shown, the elastic body strain device for the load sensor includes: a first fixing seat 100, a second fixing seat 200 and a strain column 300; the first fixing seat 100 and the second fixing seat 200 are respectively located at two ends of the strain column 300; the strain column 300 is an I-beam structure, and the strain column 300 includes a web 310 and two flange plates 320, and the opposite ends of the web 310 are respectively connected to the first fixing seat 100 and the second fixing seat 200, and the opposite ends of the flange plate 320 are respectively connected to the first fixing seat 100 and the second fixing seat 200.

[0031] The present application is applicable to the design and processing of a large-range, three-component load sensor. The first fixing seat 100 and the second fixing seat 200 are respectively connected to the device to be tested, and are used to bear the pressure to be tested. The strain column 300 undergoes elastic deformation under the pressure. Compared with the traditional strain column 300 with a rectangular columnar structure in cross section, the present application designs the strain column 300 as an I-beam structure, which greatly improves its ability to resist eccentric loads and restrains the local deformation produced in the area where the upper end face is subjected to concentrated force. Because of the characteristics of the I-beam structure itself, the unbalanced stress will be redistributed, and the web 310 will produce considerable tension and delay the development of deflection, making the overall force of the strain column 300 more reasonable and balanced, thereby improving the anti-eccentric load capability of the adapted sensor.

[0032] Furthermore, the strain column 300 of the I-beam structure reduces fatigue fracture of the adapted sensor under special circumstances and improves the static performance of the adapted sensor.

[0033] In a possible implementation, there are more than two strain rods 300, and the more than two strain rods 300 are arranged in a circle. Those skilled in the art can set the number of strain rods 300 according to the type of sensor to be adapted, so that the number of strain rods 300 matches the number of strain gauges of the adapted sensor.

[0034] like Figure 1 and Figure 2 As shown, the first fixing seat 100 is provided with a first connecting portion 110 and a first fixing portion 120, and the second fixing seat 200 is provided with a second connecting portion 210 and a second fixing portion 220; the first connecting portion 110 and the second connecting portion 210 are respectively connected to two ends of the strain column 300; the first fixing portion 120 and the strain column 300 are respectively located on opposite sides of the first connecting portion 110; the second fixing portion 220 and the strain column 300 are respectively located on opposite sides of the second connecting portion 210. The first fixing seat 100 and the second fixing seat 200 are respectively connected to the device to be tested through the first fixing portion 120 and the second fixing portion 220, and the overall structure is relatively simple, which effectively reduces the production cost.

[0035] In a possible implementation, the first connection part 110 and the second connection part 210 are both cylindrical structures, and the two ends of the strain column 300 are respectively connected to the end face of the first connection part 110 and the end face of the second connection part 210; the first fixing part 120 and the second fixing part 220 are both rectangular structures, the first connection part 110 is located in the middle of one side of the first fixing part 120, and the second connection part 210 is located in the middle of one side of the second fixing part 220. It should be noted that although the above application is introduced as an example, those skilled in the art can understand that the present application should not be limited to this. In fact, the user can flexibly set the specific structure of the first connection part 110, the second connection part 210, the first fixing part 120 and the second fixing part 220 according to the range of the object to be measured or the installation requirements of the actual application scenario, as long as it can meet the use in any complex environment.

[0036] Furthermore, the first fixing portion 120 and the second fixing portion 220 are each provided with more than two mounting holes. The first fixing portion 120 and the second fixing portion 220 are respectively mounted to the device to be tested through the mounting holes thereof.

[0037] The two or more mounting holes of the first fixing portion 120 are arranged in a rectangular shape around the first connecting portion 110 , and the two or more mounting holes of the second fixing portion 220 are arranged in a rectangular shape around the second connecting portion 210 .

[0038] Preferably, the first fixing portion 120 and the second fixing portion 220 are each provided with twelve mounting holes.

[0039] It should be noted here that, preferably, the sensor adapted by the present application is a four-column sensor, and therefore, there are four strain columns 300 , which are arranged in a square and are respectively located at the four corners of the square.

[0040] In a possible implementation, the four strain rods 300 are respectively close to the end surface edges of the first connection portion 110 to increase the distance between the four strain rods 300 and further improve the overall lateral resistance capability of the present application.

[0041] Furthermore, compared to the traditional rectangular cross-section structure, the I-beam strain column 300 of the present application greatly improves the lateral resistance, torsional rigidity and shear strength. The cross-section of the I-beam structure is more open, the moment of inertia of the cross-section is larger, and the bending bearing capacity of the strain column 300 is correspondingly improved. Secondly, the pressure acting on the measuring unit is reduced, the resistance strain type material of the strain column 300 is prevented from being damaged, the working stability of the force sensor is improved, and the service life and recycling cycle of the force sensor are extended. Finally, the I-beam strain column 300 is used as the supporting structure of the three-component force sensor. Even if the sensor fails during operation, due to the strong lateral resistance of the I-beam structure, there will be obvious deformation before the damage occurs, and manual compensation and trimming can be done, and there will be no sudden failure like the traditional four-column structure.

[0042] Furthermore, the strain column 300 is designed as an I-beam structure. Compared with the traditional rectangular cross-section structure, the traditional three-component force sensor has a range ratio of x:y:z of 1:1:5 in three directions. The I-beam structure can increase the range of the lateral force of the three-component sensor by 80%. The range ratio of x:y:z in three directions of the improved structure is 1:1:1, which greatly improves the measurement range and usage scenarios.

[0043] In addition, the strain column 300 of the I-beam structure is more sensitive to deformation, especially for the three-component force sensor, which effectively solves the problem of mutual interference between dimensions, ensures that the influence of crosstalk between mutual forces is reduced to within the error range, and greatly improves the measurement accuracy of the three-component force sensor.

[0044] Compared with the traditional strain column 300 with a regular rectangular cross-section structure, the strain column 300 with an I-beam structure of the present application not only enhances the rigidity of the sensor, but also, because the I-beam support structure has a smaller total mass and inertia than the columnar regular rectangular cross-section structure, it effectively improves the sensitivity and response speed of the sensor greatly, and can also improve the dynamic response frequency of the sensor.

[0045] Generally, the four-column rectangular cross-sectional structure strain column 300 is mostly suitable for single-component force sensors, which have a large measurement range, are easy to assemble, have simple one-piece processing, and have low requirements for lateral output and anti-eccentricity and anti-biased load capabilities. However, for complex environmental scenarios, such as robot finger and gripper research, precision assembly, cutting, smart car manufacturing, automated assembly line assembly, aerospace and other fields, first of all, high requirements are placed on the installation position and sensor structure and weight. Secondly, these application scenarios require three-component or even multi-component output forces and torques to a large extent. However, the three-component force sensors designed at this stage are mostly four-column rectangular cross-sectional area structures. When detecting eccentric force or torque, the unstable changes in the force point will have a great impact on the output, resulting in low measurement accuracy and poor stability of the three-component force sensor. In particular, there is a large mutual interference problem between multiple dimensions, which further increases the measurement error and shortens the measurement range.

[0046] In one possible implementation, see Figure 5 The web 310 of the strain column 300 is provided with a thickness a, and the flange plate 320 of the strain column 300 is provided with a preset thickness b. Combining the theoretical data calculation and the test analysis results, it is suggested that the width-to-thickness ratio of the flange plate 320 is: W / b<13, and the height-to-thickness ratio of the web 310 is: h / a<80.

[0047] In a possible implementation, the main body of the strain column 300 is a columnar structure, and grooves are respectively provided on two opposite sides of the strain column 300. By providing buffer grooves on two opposite sides of the strain column 300, the strain column 300 forms an I-beam structure, which is relatively simple in processing and effectively reduces production costs.

[0048] Furthermore, the main body of the strain column 300 is a rectangular column structure, and the two buffer grooves provided on opposite sides of the strain column 300 are both oblong hole structures, and the length direction of the buffer groove is the same as the axial direction of the strain column 300. Figure 3 and Figure 4 As shown, by providing oblong holes on two opposite sides of the strain column 300, an I-beam structure is formed in the middle of the strain column 300, and the two end surfaces of the strain column 300 remain rectangular, so that the strain column 300 has the structural advantages of the I-beam and has a larger contact area with the first connecting portion 110 and the second connecting portion 210, thereby having better connection stability.

[0049] It should be noted here that the main body of the strain column 300 is a rectangular column structure, that is, its end face is a square, and its square end face is provided with a preset side length A, the strain column 300 is provided with a preset length B, and the body length direction of the oblong hole is provided with a preset length C. Technical personnel in this field can set this according to the actual installation environment and working range.

[0050] See also Figure 2 and Figure 4 , the webs 310 of the two or more strain columns 300 are arranged parallel to each other. That is, the side faces of the two or more strain columns 300 are oriented in the same direction. The four strain columns 300 are arranged in a square, and the right angles of the end faces of the four strain columns 300 coincide with the four right angles of the square. The square formed by the four strain columns 300 has a preset side length of L.

[0051] It is suggested that from the perspective of improving the dynamic frequency response of the sensor, the relationship between the preset length B of the strain column 300 and the preset side length L of the square formed by the strain column 300 is B / L≥2; the determination of the preset side length A of the square end face of the strain column 300 and the preset length C in the long direction of the oblong hole body mainly depends on the actual installation size and working range.

[0052] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. An elastic body strain structure for a load sensor, suitable for the design and processing of a large-range, three-component load sensor, elastically deformed under pressure, characterized in that: include: A first fixing seat, a second fixing seat and a strain column; The first fixing seat and the second fixing seat are respectively located at two ends of the strain column; The strain column is an I-beam structure, and includes a web and two flange plates, the opposite ends of the web are respectively connected to the first fixing seat and the second fixing seat, and the opposite ends of the flange plate are respectively connected to the first fixing seat and the second fixing seat; the web is provided with a thickness a, and the flange plate is provided with a preset thickness b, the width-to-thickness ratio of the flange plate is: W / b<13, and the height-to-thickness ratio of the web is: h / a<80; There are four strain columns, which are arranged in an equilateral rectangle, and are respectively located at four corners of the equilateral rectangle; the relationship between a preset length B of the strain column and a preset side length L of the equilateral rectangle formed by the strain column is B / L≥2; The webs of the four strain columns are arranged parallel to each other; The first fixing seat is provided with a first connecting portion and a first fixing portion, and the second fixing seat is provided with a second connecting portion and a second fixing portion; The first connection portion and the second connection portion are respectively connected to two ends of the strain column; The first fixing portion and the strain column are respectively located at two opposite sides of the first connecting portion; The second fixing portion and the strain column are respectively located at two opposite sides of the second connecting portion; The first connection part and the second connection part are both cylindrical structures, and two ends of the strain column are respectively connected to the end surface of the first connection part and the end surface of the second connection part; The first fixing portion and the second fixing portion are both rectangular structures, the first connecting portion is located in the middle of one side of the first fixing portion, and the second connecting portion is located in the middle of one side of the second fixing portion.

2. The elastic body strain structure for a load sensor according to claim 1, characterized in that: The first fixing portion and the second fixing portion are each provided with more than two mounting holes.

3. The elastic body strain structure for a load sensor according to claim 1, characterized in that: The four strain columns are respectively close to the end surface edges of the first connecting portion.

4. The elastic body strain structure for a load sensor according to any one of claims 1 to 3, characterized in that: The main body of the strain column is a columnar structure, and buffer grooves are respectively provided on two opposite side surfaces of the strain column.

5. The elastic body strain structure for a load sensor according to claim 4, characterized in that: The main body of the strain column is a rectangular column structure, and the two buffer grooves arranged on opposite sides of the strain column are both oblong hole structures, and the length direction of the buffer groove is the same as the axial direction of the strain column.

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