A six-dimensional force sensor

Abstract

The utility model provides a kind of six-dimensional force sensor, including elastomer, the elastomer is sequentially arranged inner column, annular part and shell from inside to outside, the outer circumferential surface of annular part is integrally formed support, the end of support away from annular part is inserted into the inner wall groove of shell, and is connected with the groove. Annular part and support of the application are integrally formed, on the one hand, it can be used to connect elastic beam and shell, for buffering and dispersing overload force, improve the overall stiffness of elastomer, and then improve the anti-overload capacity, on the other hand, the support can effectively protect the annular part, and the support is inserted into the groove, increase the contact area of annular part and shell, make the connection of the two more stable and not easy to loosen and fall off, so as to prevent being subjected to larger impact load, thinner wall thickness annular part is easy to damage. The overall strength and sensitivity of the six-dimensional force sensor of the application consider elastomer.

Description

Technical Field

[0001] This utility model relates to the field of sensors, and more specifically, to a six-dimensional force sensor. Background Technology

[0002] A six-dimensional force sensor is a high-precision sensor that can simultaneously detect force and torque components in three directions (X / Y / Z axes) in a Cartesian coordinate system. It is widely used in industrial robots, humanoid robots, precision manufacturing and other fields.

[0003] The core measurement structure of the existing six-dimensional force sensor mainly consists of a floating end, an integral elastomer structure, a circuit board, and a cover plate. The integral elastomer structure is further divided into an outer ring shell, an inner column, and an elastic beam. One end of the elastic beam is connected to the inner column, and the other end is connected to the outer ring shell.

[0004] During use, six-dimensional force sensors are susceptible to damage in harsh industrial environments where robots are prone to falls and collisions. These unpredictable factors can subject the sensor to sudden, significant impact loads, potentially damaging the elastomer or causing abnormal sensor output. Current six-dimensional force sensors have relatively poor overload resistance, typically around three times their rated load, rarely reaching five times. As a core force sensing element in robot end-effectors, overload damage to the six-dimensional force sensor can lead to malfunctions and even significant safety hazards, thus limiting its application scenarios.

[0005] CN112747854B describes a six-dimensional force sensor comprising an inner ring, an outer ring, and elastic beams. The inner ring is placed inside the outer ring, and the elastic beams are evenly spaced along the circumference between the inner and outer rings. Under large impact loads, this type of six-dimensional force sensor lacks sufficient stiffness and is easily damaged. Utility Model Content

[0006] In view of this, the present invention aims to propose a six-dimensional force sensor to solve the problems of insufficient stiffness, poor overload resistance, and easy damage of existing six-dimensional force sensors.

[0007] To achieve the above objectives, the technical solution of this utility model is implemented as follows:

[0008] A six-dimensional force sensor includes an elastomer. From the inside out, the elastomer comprises an inner column, an annular component, and a shell. A support member is integrally formed on the outer circumferential surface of the annular component. The end of the support member furthest from the annular component extends into a groove in the inner wall of the shell and connects with the groove. The annular component and support member are integrally formed, which serves two purposes: firstly, it connects the elastic beam and the shell, buffering and dispersing overload forces, improving the overall stiffness of the elastomer, and thus enhancing its overload resistance; secondly, the support member effectively protects the annular component, and its insertion into the groove increases the contact area between the annular component and the shell, making the connection more stable and less prone to loosening or detachment, thereby preventing damage to the thin-walled annular component under large impact loads. This six-dimensional force sensor balances the overall strength and sensitivity of the elastomer.

[0009] Furthermore, the inner column and the annular component are connected by an elastic beam. The elastic beam includes a first connecting end that fits snugly against the outer wall of the inner column and a second connecting end that fits snugly against the inner wall of the annular component. The left side of the first connecting end and the left side of the second connecting end are connected by a first side surface, and the right side of the first connecting end and the right side of the second connecting end are connected by a second side surface. The first and second side surfaces are curved or inclined surfaces. When a load is applied to subject the elastic body to forces in different directions, the curved or inclined elastic beam, due to its varying cross-sectional area, facilitates the formation of stress concentration areas. Therefore, it can sense forces from different directions and generate strain without requiring additional holes, slots, or other structures of different shapes and positions on the elastic beam to generate different strains in different directions, thus reducing the impact on the overall strength and stiffness of the elastic body. In addition, this configuration can actively guide and concentrate stress, causing stress to concentrate more in specific areas of curvature change or tilting. This allows strain gauges located in these areas to sense stronger deformation signals, improving detection sensitivity.

[0010] Furthermore, the area of ​​the first connecting end is larger than the area of ​​the second connecting end, and a strain gauge is placed near the first connecting end. The first connecting end connects to the inner column, and the external load acts on the sensor through the inner column, causing deformation of the elastic beam. Therefore, as the first connecting end is in contact with the inner column, the deformation of the elastic beam is more likely to concentrate near the first connecting end. Thus, increasing the area of ​​the first connecting end not only improves the connection stability but also allows for more effective transmission of external forces, promoting deformation and concentrating the deformation of the elastic beam at the first connecting end. Accordingly, placing a strain gauge near the first connecting end allows the strain gauge to better sense force and / or torque.

[0011] Furthermore, the support member is connected to the application end via a first connector. This not only positions the elastomer on the application end, but also, because the first connector links the support member and the application end, it better constrains the second connecting end connected to the annular member, reducing deformation of the second connecting end and allowing the first connecting end to deform more effectively. The strain gauge positioned near the first connecting end can output force data and / or torque data based on the degree of deformation at that location, improving the detection sensitivity of the six-dimensional force sensor.

[0012] Furthermore, multiple elastic beams are arranged radially along the radial direction of the annular component, and multiple support members are also arranged radially along the radial direction of the annular component, with the elastic beams and support members spaced apart. Multiple elastic beams share the load, improving detection sensitivity. Multiple support members better support the annular component and improve the buffering and dispersing of overload forces, contributing to the stiffness and overload resistance of the six-dimensional force sensor.

[0013] Furthermore, four elastic beams are provided, arranged in a cross shape, and eight support members are provided, with the elastic beams and support members equally spaced. This arrangement makes the six-dimensional force sensor structure more symmetrical, ensures uniform force distribution, reduces inter-dimensional coupling, and saves raw materials while ensuring high detection sensitivity and overload resistance.

[0014] Furthermore, the inner column is provided with multiple wiring channels. These channels are used to constrain and organize the wiring harness of the six-dimensional force sensor, preventing the unconstrained wiring harness from randomly encountering the elastic beam when measuring force and / or torque, thus generating an irregular force exerted by the wiring harness on the elastic beam from within, leading to measurement errors, and also preventing the wiring harness from tangling with each other.

[0015] Furthermore, the six-dimensional force sensor also includes a floating cover, a circuit board, and a cover plate. The floating cover and the cover plate are respectively disposed at opposite ends of the elastomer. The circuit board is located between the elastomer and the cover plate, and the circuit board is connected to the elastomer.

[0016] Furthermore, the floating cover is connected to the inner column via a second connector. The floating cover has multiple first screw holes evenly distributed along its circumference, and is connected to a force-applying device through these first screw holes. The force-applying device applies force to the floating cover, causing the inner column connected to the floating cover to be stressed, which in turn causes deformation of the elastic beam and a corresponding change in the resistance of the strain gauge.

[0017] Furthermore, the second connector is a stud. Multiple second screw holes are evenly distributed around the center of the floating cover along the circumferential direction, and multiple third screw holes are correspondingly provided on the inner post. The second connector passes through the second and third screw holes to connect the floating cover and the inner post.

[0018] Compared with existing technologies, the six-dimensional force sensor described in this utility model has the following advantages:

[0019] (1) The ring and the support are integrally formed in this application. On the one hand, they can be used to connect the elastic beam and the shell to buffer and disperse overload force, improve the overall stiffness of the elastic body, and thus improve the overload resistance. On the other hand, the support can effectively protect the ring and the support extends into the groove, increasing the contact area between the ring and the shell, making the connection between the two more stable and less prone to loosening and falling off, thereby preventing the thin-walled ring from being easily damaged when subjected to large impact loads.

[0020] (2) Increasing the area of ​​the first connection end not only improves the connection stability, but also enables the external force to be transmitted more effectively, promoting deformation and concentrating the deformation of the elastic beam at the first connection end. Accordingly, strain gauges are placed near the first connection end to better sense the force and / or torque.

[0021] (3) The support is connected to the application end through the first connector, which can better constrain the second connecting end connected to the ring, reduce the deformation of the second connecting end, and make the first connecting end deform better. The strain gauge set near the first connecting end can output force data and / or torque data according to the degree of deformation here, thereby improving the detection sensitivity of the six-dimensional force sensor. At the same time, the ring is further strengthened and tightened at the support through the action of the first connector, which is beneficial to the stiffness of the ring and thus protects the ring.

[0022] (4) Multiple wiring channels are provided in the inner column to constrain and organize the wiring harness of the six-dimensional force sensor, prevent the wiring harness from getting tangled, alleviate the situation where the wiring shifts due to positional deviation under harsh working conditions, reduce the risk of interference between circuits introducing additional interference force during measurement, and thus improve measurement accuracy. Attached Figure Description

[0023] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an undue limitation of the utility model. In the drawings:

[0024] Figure 1 This is a schematic diagram of the structure of the six-dimensional force sensor described in this utility model;

[0025] Figure 2 This is an exploded view of the six-dimensional force sensor described in this utility model;

[0026] Figure 3 This is a first-view structural schematic diagram of the elastomer described in this utility model;

[0027] Figure 4 for Figure 3 A schematic diagram of an elastic body with a portion of its support removed;

[0028] Figure 5 This is a second-view structural schematic diagram of the elastomer described in this utility model.

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

[0030] 1. Floating cover; 11. First screw hole; 2. Elastomer; 21. Housing; 22. Ring-shaped component; 23. Elastic beam; 231. First connecting end; 232. Second connecting end; 233. First side; 234. Second side; 24. Support component; 25. Wiring trough; 26. Inner column; 3. Circuit board; 4. Cover plate; 5. First connector; 6. Second connector. Detailed Implementation

[0031] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. In addition, the orientations involved in the following specific embodiments are briefly explained: the directions or positional relationships indicated by "front," "rear," "up," "down," "left," "right," "top," and "bottom" mentioned in the embodiments refer to the orientations or positional relationships shown in the accompanying drawings. The term "on..." means directly or indirectly supported by the... element.

[0032] It should be noted that, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for mutual communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0033] like Figures 1-5 As shown, a six-dimensional force sensor of this application includes an elastic body 2. The elastic body 2 is provided with an inner column 26, an annular member 22 and a housing 21 from the inside to the outside. The outer peripheral surface of the annular member 22 is integrally formed with a support member 24. One end of the support member 24 away from the annular member 22 extends into the inner wall groove of the housing 21 and is connected to the groove.

[0034] Due to space constraints in the elastomer 2 and the need for displacement and deformation of the elastic beam 23 connected to the annular member 22, the wall thickness of the annular member 22 is less than that of the shell 21. This not only ensures that the annular member 22 does not occupy excessive space but also avoids difficulties in displacement and deformation of the elastic beam 23 due to excessive wall thickness, which would affect the detection sensitivity. In this application, the annular member 22 and the support member 24 are integrally formed. On one hand, they connect the elastic beam 23 and the shell 21, buffering and dispersing overload forces, improving the overall stiffness of the elastomer 2, and thus improving overload resistance. On the other hand, the support member 24 effectively protects the annular member 22, and its insertion into the groove increases the contact area between the annular member 22 and the shell 21, making the connection more stable and less prone to loosening or detachment. This prevents the thin-walled annular member 22 from being easily damaged under large impact loads. The six-dimensional force sensor of this application balances the overall strength and sensitivity of the elastomer 2.

[0035] Specifically, the wall thickness of the annular component 22 is 1 / 3 of the wall thickness of the housing 21.

[0036] Tests have shown that by adding the ring component 22 and the support component 24, the full-scale range of the six-dimensional force sensor can be increased from 300% to approximately 500%.

[0037] Strain gauges are installed on each elastic beam 23. The load is applied to the six-dimensional force sensor through the inner column 26, causing deformation of the elastic beam 23. This deformation is then transmitted to the strain gauges, which convert the deformation of the elastic beam 23 into an electrical signal for measurement. The combined action of multiple strain gauges improves the fault tolerance of the six-dimensional force sensor and enhances detection reliability. Specifically, the strain gauges are bonded to the elastic beam 23.

[0038] As a preferred example of this application, the inner column 26 and the annular member 22 are connected by an elastic beam 23. The elastic beam 23 includes a first connecting end 231 that is fitted to the outer wall of the inner column 26 and a second connecting end 232 that is fitted to the inner wall of the annular member 22. The left side of the first connecting end 231 and the left side of the second connecting end 232 are connected by a first side surface 233, and the right side of the first connecting end 231 and the right side of the second connecting end 232 are connected by a second side surface 234. The first side surface 233 and the second side surface 234 are curved or inclined surfaces.

[0039] When a load is applied to subject the elastic body 2 to forces in different directions, the curved or inclined elastic beam 23, due to its varying cross-sectional area, facilitates the formation of stress concentration areas. Therefore, it can sense forces from different directions and generate strain without requiring additional holes, slots, or other structures of different shapes and locations on the elastic beam 23 to produce differentiated strains in different directions, thus reducing the impact on the overall strength and stiffness of the elastic body 2. Furthermore, this configuration can actively guide and concentrate stress, causing it to concentrate more in specific areas of curvature change or tilting. This allows strain gauges located within these areas to detect stronger deformation signals, improving detection sensitivity.

[0040] To further improve the stiffness of the elastomer 2, the shell 21, the ring 22, the elastic beam 23, the support 24 and the inner column 26 are integrally formed, which better improves the overload resistance.

[0041] As a preferred example of this application, the area of ​​the first connection end 231 is larger than the area of ​​the second connection end 232, and a strain gauge is disposed near the first connection end 231.

[0042] Since the second connecting end 232 is connected to the annular component 22, a relatively stable connection system is established between the second connecting end 232 and the housing 21 through the annular component 22. Therefore, the area of ​​the second connecting end 232 does not need to be too large. The first connecting end 231 is connected to the inner column 26. The external load acts on the sensor through the inner column 26, causing the elastic beam 23 to deform. Therefore, as the first connecting end 231 is in contact with the inner column 26, the deformation of the elastic beam 23 is more likely to concentrate near the first connecting end 231. Therefore, increasing the area of ​​the first connecting end 231 not only helps to improve the connection stability between the two, but also enables the external force to be transmitted more effectively, promoting deformation and concentrating the deformation of the elastic beam 23 at the first connecting end 231. Accordingly, a strain gauge is set near the first connecting end 231 to better sense the force and / or torque. The strain of the elastic beam 23 is converted into an electrical signal by the strain gauge for measurement, achieving the purpose of measuring the force and / or torque.

[0043] The support member 24 is connected to the application end via the first connector 5. This not only positions the elastomer 2 on the application end, but also, because the first connector 5 connects the support member 24 to the application end, it better constrains the second connecting end 232 connected to the annular member 22, reducing the deformation of the second connecting end 232. This allows the first connecting end 231 to deform more effectively. The strain gauge positioned near the first connecting end 231 can output force data and / or torque data based on the degree of deformation at that location, improving the detection sensitivity of the six-dimensional force sensor.

[0044] Furthermore, in existing technologies, the housing 21 is usually connected to the application end via the first connector 5. In this application, the support member 24, as part of the annular member 22, further strengthens and secures the annular member 22 at the support member 24 through the action of the first connector 5, which is beneficial to the rigidity of the annular member 22 and thus protects the annular member 22. Specifically, in this application... Figures 2-4 In this context, the first connecting member 5 is a stud.

[0045] The application described in this application refers to the robotic arm, worktable, support platform, etc. of a robot.

[0046] Multiple elastic beams 23 are arranged radially along the radial direction of the annular component 22, and multiple support members 24 are arranged radially along the radial direction of the annular component 22, with the elastic beams 23 and support members 24 spaced apart. Multiple elastic beams 23 share the load, improving detection sensitivity. Multiple support members 24 better support the annular component 22 and improve the buffering and dispersing of overload forces, contributing to the stiffness and overload resistance of the six-dimensional force sensor. In this application, the number of elastic beams 23 and support members 24 is not specifically limited, as long as they are reasonably arranged and detection sensitivity and stiffness are guaranteed. The number of support members 24 can be 4, 8, 12, 16, 20, etc.

[0047] As a preferred example of this application, four elastic beams 23 are provided, and the four elastic beams 23 are distributed in a cross shape. Eight support members 24 are provided, and the elastic beams 23 and the support members 24 are distributed at equal intervals. This arrangement makes the six-dimensional force sensor structure more symmetrical, the force is evenly distributed, and the inter-dimensional coupling is reduced. It saves raw materials while ensuring high detection sensitivity and overload resistance.

[0048] As a preferred example of this application, the inner column 26 is provided with multiple wiring slots 25 for constraining and organizing the wiring harness of the six-dimensional force sensor, preventing the wiring harness from tangling with each other, mitigating the situation where the wiring shifts due to positional displacement under harsh working conditions, reducing the risk of interference between circuits introducing additional interference forces during measurement, and thus improving measurement accuracy. The number of wiring slots 25 can be any integer between 1 and 40.

[0049] To better position the wire harness, the wire harness and the wiring channel 25 are bonded together with adhesive.

[0050] The six-dimensional force sensor also includes a floating cover 1, a circuit board 3, and a cover plate 4. The floating cover 1 and the cover plate 4 are respectively disposed at opposite ends of the elastic body 2. The circuit board 3 is located between the elastic body 2 and the cover plate 4, and the circuit board 3 is connected to the elastic body 2. The floating cover 1 is connected to the inner column 26 at the top of the elastic body 2, and the cover plate 4 is connected to the housing 21 at the bottom of the elastic body 2.

[0051] As a preferred example of this application, the floating cover 1 is connected to the inner column 26 via the second connector 6. The floating cover 1 has a plurality of first screw holes 11 evenly arranged along its circumference, and is connected to a force-applying device via the first screw holes 11. The force-applying device applies force to the floating cover 1, causing the inner column 26 connected to the floating cover 1 to be stressed, which in turn causes deformation of the elastic beam 23, and consequently changes the resistance of the strain gauge.

[0052] Specifically in this application 1-2, the second connecting member 6 is a stud, and the center of the floating cover 1 is uniformly provided with a plurality of second screw holes along the circumferential direction. The inner column 26 is provided with a plurality of third screw holes. The second connecting member 6 passes through the second screw holes and the third screw holes to realize the connection between the floating cover 1 and the inner column 26.

[0053] The first screw hole 11 is located near the edge of the floating cover 1, and the second screw hole is located near the center of the floating cover 1, thus making a reasonable arrangement of the first screw hole 11 and the second screw hole.

[0054] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of the present invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A six-dimensional force sensor, comprising an elastic body (2), characterized in that, The elastic body (2) is provided with an inner column (26), an annular member (22) and a shell (21) from the inside to the outside. The outer peripheral surface of the annular member (22) is integrally formed into a support member (24). The end of the support member (24) away from the annular member (22) extends into the inner wall groove of the shell (21) and is connected to the groove.

2. The six-dimensional force sensor according to claim 1, characterized in that, The inner column (26) and the ring member (22) are connected by an elastic beam (23). The elastic beam (23) includes a first connecting end (231) that is fitted to the outer wall of the inner column (26) and a second connecting end (232) that is fitted to the inner wall of the ring member (22). The left side of the first connecting end (231) and the left side of the second connecting end (232) are connected by a first side surface (233). The right side of the first connecting end (231) and the right side of the second connecting end (232) are connected by a second side surface (234). The first side surface (233) and the second side surface (234) are curved or inclined.

3. The six-dimensional force sensor according to claim 2, characterized in that, The area of ​​the first connecting end (231) is larger than the area of ​​the second connecting end (232), and a strain gauge is provided near the first connecting end (231).

4. The six-dimensional force sensor according to claim 1, characterized in that, The support member (24) is connected to the application end via the first connector (5).

5. The six-dimensional force sensor according to claim 2, characterized in that, Multiple elastic beams (23) are arranged radially along the radial direction of the annular member (22), and multiple support members (24) are arranged radially along the radial direction of the annular member (22), with the elastic beams (23) and support members (24) distributed at intervals.

6. The six-dimensional force sensor according to claim 5, characterized in that, Four elastic beams (23) are provided, and the four elastic beams (23) are distributed in a cross shape. Eight support members (24) are provided, and the elastic beams (23) are distributed at equal intervals, and the support members (24) are distributed at equal intervals.

7. The six-dimensional force sensor according to claim 1, characterized in that, The inner column (26) is provided with multiple cable trays (25).

8. The six-dimensional force sensor according to claim 1, characterized in that, The six-dimensional force sensor also includes a floating cover (1), a circuit board (3) and a cover plate (4). The floating cover (1) and the cover plate (4) are respectively disposed at opposite ends of the elastic body (2). The circuit board (3) is located between the elastic body (2) and the cover plate (4), and the circuit board (3) is connected to the elastic body (2).

9. The six-dimensional force sensor according to claim 8, characterized in that, The floating cover (1) is connected to the inner column (26) through the second connector (6). The floating cover (1) is provided with a plurality of first screw holes (11) evenly along the circumferential direction. The floating cover (1) is connected to the force application device through the first screw holes (11).

10. The six-dimensional force sensor according to claim 9, characterized in that, The second connector (6) is a stud.

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