CN219084269U - Force sensor - Google Patents

Abstract

A force sensor is provided. The force sensor includes an elastomer and at least 2N strain gauges. The elastic body comprises a fixing part, a stress part and 2N elastic beams, wherein N is an integer and is more than or equal to 1. The fixed part is arranged around the outer periphery of the force-bearing part, and the 2N elastic beams are symmetrically arranged and connected between the force-bearing part and the fixed part. Wherein each elastic beam is provided with a circular arc-shaped upper surface which is connected between the top surface of the stress part and the top surface of the fixing part. And 2N strain gauges spatially corresponding to the 2N elastic beams, wherein each strain gauge is arranged on the side wall of the corresponding elastic beam. When force is applied to the force receiving part along the axial direction, the force receiving part drives the elastic beam and the strain gauge to change shape so as to measure the force in the primary range and reduce the maximum stress value generated by the force through the arc-shaped upper surface.

Description

Force sensor

Technical Field

The present disclosure relates to a force sensor, and more particularly to an elastic body and a force sensor using the same, which can prevent the elastic body from being damaged due to excessive stress concentration by using the arc-shaped upper surface and the arc-shaped lower surface of the elastic beam, thereby effectively prolonging the service life of the product.

Background

The function of the force sensor is to convert a force such as tension, pressure or torque force into an electronic signal that can be measured and standardized. As the force applied to the force sensor increases, the electronic signal will change proportionally. Among them, the strain gauge force sensor (Strain gauge load cell) is the most common one in industrial environments because of its high accuracy, multiple functionality, and cost effectiveness. The structure of the traditional strain gauge force sensor comprises an elastic body and a strain gauge, wherein the strain gauge is fixed on an elastic beam of the elastic body. The elastomer is made of, for example, aluminium, alloy steel or stainless steel, which makes it very strong but also elastic at a minimum. When the force sensor is stressed, the elastic beam of the elastic body is slightly deformed, and the strain gauge arranged on the elastic beam also changes shape, so that the resistance in the strain gauge is changed. The change in resistance in the strain gauge can be used to measure voltage. Since the voltage varies in proportion to the force applied to the force sensor, the magnitude of the force can be calculated from the output of the force sensor.

The elastic body of the traditional disc type force sensor mainly comprises an inner ring stress part, an outer ring fixing part and a plurality of groups of elastic beams. The elastic beam is connected between the stress part and the fixed part in a rectangular shape so as to be convenient for attaching the strain gauge to the side wall of the elastic beam. However, when the stress part is stressed to drive the elastic beam to deform, the connection turning part of the elastic beam and the stress part or the connection turning part of the elastic beam and the fixing part is easy to generate excessive stress, so that damage is caused, and the service life of the force sensor is influenced. On the other hand, the range of the force sensor for measuring the load acting force is mainly influenced by the size of the elastic beam, and the size of the elastic beam of the finished elastic body is fixed and is not easy to adjust and change.

In view of the foregoing, it is necessary to provide an elastic body and a force sensor suitable for the same, which utilize the circular arc upper surface and the circular arc lower surface to strengthen the structure of the elastic beam, avoid the phenomenon of excessive stress concentration at the connection transition part when the elastic beam is stressed, effectively prolong the service life of the force sensor, and solve the foregoing problems.

Disclosure of Invention

The present disclosure is directed to an elastomer and a force sensor using the same. Because the elastic Liang Cai circular arc upper surface and circular arc lower surface that the elastomer provided are designed, when of course the elastomer atress drives the elastic beam and attached strain gauge deformation on it, the elastic beam accessible circular arc upper surface and circular arc lower surface's structure dispersion stress, avoid the excessive concentrated of stress and damage, effectively promote the life of product.

Another object of the present utility model is to provide a disc type force sensor for measuring the load force in the primary range, and preventing the force sensor from being damaged due to irreversible permanent deformation caused by overload. In order to avoid irreversible permanent deformation and material damage of the force sensor caused by overload, the force sensor also introduces a step structure between the displacement bottom surface of the stress part of the elastic body and the limit bottom surface of the bottom cover, and the spacing distance formed by the step structure is more than or equal to 2 times of the full-load deformation distance of the stress part. When the force sensor is fixed on a fixing surface through the bottom cover, the fixing surface enables the stress part of the force sensor to deform in a certain space. The force sensor can be prevented from being damaged due to overload deformation under the action of supporting and limiting displacement by the fixing surface fixed by the bottom cover. In addition, the upper cover and the bottom cover are locked on the fixing part of the elastic body and also correspond to the strain gauge fixed on the elastic beam in space, so that when the upper cover and the bottom cover are locked and cover the strain gauge, the strain gauge is further protected from being polluted by dust.

The present disclosure is directed to an elastomer and a force sensor using the same. The maximum load step range of the force sensor can be adjusted by the beam width of the elastic beam. When the force sensor needs to be adjusted to different step ranges, the elastic body with different elastic beam widths does not need to be replaced, and only the arc-shaped upper surface or the arc-shaped lower surface of the elastic beam is provided with grooves or through holes with different sizes, and the resolution of 2mV/V can be maintained under different step ranges. Compared with the elastic Liang Liangkuan, the processing procedure of forming the groove or the through hole is simpler. In addition, the load step range is determined by the aperture size of the groove or the through hole, the elastomer can be pre-processed and stored, and the processing procedure of opening the groove or the through hole is performed after the required step range is confirmed, so that the product design has higher flexibility.

In order to achieve the above-mentioned objects, the present utility model provides a force sensor comprising an elastomer and at least 2N strain gauges. The elastic body comprises a fixing part, a stress part and 2N elastic beams, wherein N is an integer and is more than or equal to 1. The fixed part is arranged around the outer periphery of the force-bearing part, and the 2N elastic beams are symmetrically arranged and connected between the force-bearing part and the fixed part. Each elastic beam is provided with a circular arc-shaped upper surface, and the circular arc-shaped upper surface is connected between the top surface of the stress part and the top surface of the fixing part. At least 2N strain gauges are spatially opposite to 2N elastic beams, each strain gauge is arranged on the side wall of the corresponding elastic beam, wherein when an acting force is applied to the force receiving part from top to bottom, the force receiving part drives the 2N elastic beams and the 2N strain gauges to change shape so as to measure the acting force in a range of a first distance and reduce the maximum stress value generated by the acting force through the arc-shaped upper surface.

In an embodiment, each elastic beam has a circular arc-shaped lower surface, and the circular arc-shaped lower surface is connected between the displacement bottom surface of the stress portion and the bottom surface of the body of the fixing portion.

In an embodiment, the force sensor includes a bottom cover, and a bottom surface of the body connected to the fixing portion, and covers a circular arc lower surface of the 2N elastic beams, wherein a level difference structure is further formed between a limiting bottom surface of the bottom cover and a displacement bottom surface of the force receiving portion in a radial direction.

In an embodiment, when the force receiving portion is displaced toward the bottom cover in the axial direction due to the acting force, the force receiving portion has a full load displacement distance within the step size range, and the step structure has a spacing distance in the axial direction, wherein the spacing distance is greater than or equal to 2 times the full load deformation distance.

In one embodiment, the force sensor includes a signal processor disposed on the elastic body and electrically connected to at least 2N strain gauges, and the power sensor converts analog signals generated by the 2N strain gauges into digital signals.

In one embodiment, each of the 2N elastic beams includes a groove recessed through the circular arc upper surface or the circular arc lower surface.

In one embodiment, each of the 2N spring beams has a beam width, the ratio of the beam width to the aperture of the groove is x, and x ranges from 1< x <12.

In one embodiment, each of the 2N spring beams includes a through hole penetrating the circular arc upper surface and the circular arc lower surface and being parallel to the axial direction.

In one embodiment, each of the 2N spring beams has a beam width, the ratio of the beam width to the aperture of the through hole is x, and x ranges from 1< x <12.

In one embodiment, the at least 2N strain gauges include 4N strain gauges, and the 4N strain gauges are respectively disposed on two opposite sidewalls of the 2N elastic beams.

In an embodiment, the force-bearing portion further includes a shaft hole penetrating the force-bearing portion along an axial direction.

Drawings

FIG. 1 is a perspective view of a force sensor according to a first embodiment of the present disclosure;

FIGS. 2A and 2B are exploded views showing a force sensor according to a first embodiment of the present utility model;

FIG. 3 is a schematic cross-sectional view of a force sensor according to a first embodiment of the disclosure;

FIG. 4 is an enlarged view revealing region P of FIG. 3;

FIG. 5 is a top view of the force sensor of the first embodiment without the cover;

FIG. 6 is a functional block diagram of a force sensor according to a first embodiment of the present disclosure;

FIG. 7 is a top view of a force sensor without a cover according to a second embodiment of the present disclosure;

FIG. 8 is a functional block diagram of a force sensor according to a second embodiment of the present disclosure;

FIG. 9 is a schematic illustration of the dimensions of an elastomer according to a first embodiment of the present disclosure;

FIG. 10 is a schematic illustration of the dimensions of an elastomer according to a second embodiment of the present disclosure;

FIG. 11 is a schematic illustration of the dimensions of an elastomer according to a third embodiment of the present disclosure;

FIG. 12 is a schematic dimensional view of an elastomer according to a fourth embodiment of the present disclosure;

FIG. 13 is a schematic dimensional view of an elastomer according to a fifth embodiment of the present disclosure.

[ symbolic description ]

1. 1a: force sensor

2. 2a, 2b, 2c, 2d: elastic body

10: fixing part

11: top surface

12: bottom surface of body

13: first locking hole

20: force-bearing part

21: top surface

22: displacement bottom surface

23: shaft hole

30: elastic beam

31: circular arc upper surface

32: circular arc lower surface

33. 33a, 33b: through hole

40: upper cover

41: upper cover opening

42: second locking hole

50: bottom cover

51: bottom cover opening

52: third locking hole

53: limiting bottom surface

60: step structure

3. 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h: strain gauge

4: signal processor

4a: analog-to-digital converter

4b: digital signal processor

4c: RS-485 communication interface

4d: low-dropout voltage regulator

C: center shaft

D1, D2, D3: pore diameter

F: acting force

G: distance of separation

S+, S-: signal signal

V+, V-: voltage input terminal

W1, W2: beam width

X, Y, Z: shaft

Detailed Description

Some exemplary embodiments that exhibit the features and advantages of the present disclosure are described in detail in the following description. It will be understood that various changes can be made in the above-described embodiments without departing from the scope of the utility model, and that the description and drawings are to be regarded as illustrative in nature and not as restrictive. For example, if the disclosure below describes disposing a first feature on or over a second feature, it is intended to include embodiments in which the first feature is disposed in direct contact with the second feature, as well as embodiments in which additional features may be disposed between the first feature and the second feature such that the first feature and the second feature may not be in direct contact. In addition, various embodiments of the present disclosure may use repeated reference characters and/or marks. These repetition are for the purpose of simplicity and clarity and do not in itself dictate a relationship between the various embodiments and/or configurations of the depicted items. Moreover, spatially relative terms such as "upper," "lower," "top," "bottom," and the like may be used for convenience in describing the relationship of one component or feature to another component(s) or feature(s) in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may also be otherwise positioned (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors of the spatially relative descriptors used herein interpreted accordingly. Further, when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may be present. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the disclosure are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. In addition, it is to be understood that, although the terms "first," "second," "third," etc. may be used in the claims to describe various elements, these elements should not be limited by these terms, and that these elements described correspondingly in the embodiments are represented by different reference numerals. These terms are used to distinguish one element from another. For example: a first component could be termed a second component, and, similarly, a second component could be termed a first component, without departing from the scope of the embodiments. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. Except in the operating/working examples, or where otherwise explicitly indicated, all numerical ranges, amounts, values, and percentages disclosed herein (e.g., angles, durations, temperatures, operating conditions, ratios of amounts, and the like) are to be understood as modified by the term "about" or "substantially" in all embodiments. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the present disclosure and attached claims are approximations that may vary as desired. For example, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding principles. Ranges can be expressed herein as from one endpoint to the other endpoint, or between two endpoints. All ranges disclosed herein are inclusive of the endpoints unless otherwise specified.

FIG. 1 is a perspective view of a force sensor according to a first embodiment of the present disclosure. FIGS. 2A and 2B are exploded views showing a force sensor according to a first embodiment of the present utility model. FIG. 3 is a schematic cross-sectional view of a force sensor according to a first embodiment of the present disclosure. As shown in fig. 1 to 3, the force sensor 1 of the first embodiment is, for example, a disc-type force sensor, and includes an elastomer 2 and a plurality of strain gauges 3. The elastic body 2 has a disc shape and may be made of, for example, but not limited to, aluminum, alloy steel, or stainless steel. The elastic body 2 comprises a fixing part 10, a stress part 20 and 2N elastic beams 30, wherein N is an integer and is more than or equal to 1. In the present embodiment, the present embodiment is described with 4 elastic beams 30, i.e., n=2, which is not a limitation. In the present embodiment, the fixing portion 10 is disposed around the outer periphery of the force receiving portion 20 and is disposed concentrically with respect to a central axis C, and the direction of the central axis C is, for example, parallel to the Z-axis direction, i.e., opposite to the Z-axis, and can be regarded as an axial direction. In other embodiments, the fixing portion 10 and the force receiving portion 20 may be square or have other geometric shapes, which correspond to each other. The present disclosure is not limited thereto. In the present embodiment, 2N elastic beams 30 are connected between the force receiving portion 20 and the fixing portion 10. It should be noted that, the elastic beams 30 are designed in pairs, have the same size and shape, are respectively arranged in an equidistant ring with the central axis C as the center, and extend in the radial direction and are connected between the fixing portion 10 and the force receiving portion 20. In other words, the force receiving portion 20, the elastic beam 30, and the fixing portion 10 are sequentially arranged from inside to outside. In this embodiment, each elastic beam 30 further has a circular arc-shaped upper surface 31 and a circular arc-shaped lower surface 32. The circular arc upper surface 31 is connected between the top surface 21 of the force receiving portion 20 and the top surface 11 of the fixing portion 10, and the circular arc lower surface 32 is connected between the displacement bottom surface 22 of the force receiving portion 20 and the bottom surface 12 of the body of the fixing portion 10. The circular arc upper surface 31 and the circular arc lower surface 32 may be, for example, but not limited to, circular arc structures that are symmetrical to each other and have the same size. In other embodiments, the circular arc upper surface 31 and the circular arc lower surface 32 may have different circular arc structures, and one of the circular arc upper surface 31 and the circular arc lower surface 32 may be omitted. In this embodiment, the 4N strain gauges 3, that is, the 8 strain gauges 3, are spatially disposed on two opposite sidewalls of the 4 elastic beams 30, respectively, with respect to the 4 elastic beams 30. I.e. the two opposite side walls of each elastic beam 30 are respectively provided with a corresponding strain gauge 3.

In the present embodiment, the top surface 21 of the force receiving portion 20 protrudes outwards from the top surface 11 of the fixing portion 10 to form a stepped structure. The spring beam 30 and the strain gauge 3 are arranged extending in, for example, a radial direction, which is parallel to the XY plane, different from the axial direction (i.e., the opposite direction of the Z axis). When an acting force F is applied to the top 21 of the force receiving portion 20 in the axial direction (i.e., the opposite direction of the Z axis), the force receiving portion 20 is displaced downward relative to the fixing portion 10, and drives the 2N elastic beams 30 and the 4N strain gauges 3 to change shape, so as to measure and normalize the acting force F in the primary distance range.

It should be noted that, in the present embodiment, each elastic beam 30 further has a circular arc-shaped upper surface 31 and a circular arc-shaped lower surface 32. Because the elastic beam 30 provided by the elastic body 2 adopts the design of the circular arc-shaped upper surface 31 and the circular arc-shaped lower surface 32, when the elastic body 2 is stressed to drive the elastic beam 30 and the strain gauge 3 attached to the elastic beam to deform, the elastic beam 30 can disperse stress through the structures of the circular arc-shaped upper surface 31 and the circular arc-shaped lower surface 32, so that the damage caused by excessive concentration of the stress is avoided, and the service life of a product is effectively prolonged.

In this embodiment, the force sensor 1 includes an upper cover 40 connected to the top surface 11 of the fixing portion 10 and covering the circular arc-shaped upper surfaces 31 of the 2N elastic beams 30. The fixing portion 10 includes a plurality of first locking holes 13. The upper cover 40 includes an upper cover opening 41 and a plurality of second locking holes 42. In the present embodiment, the top surface 21 of the force receiving portion 20 penetrates through the upper cover opening 41 to be exposed, so that the force F is applied to the force receiving portion 20. Of course, the present utility model is not limited thereto. In the present embodiment, the second locking holes 42 of the upper cover 40 are spatially opposite to the first locking holes 13 of the fixing portion 10. The first locking hole 13 and the corresponding second locking hole 42 may be fixed, for example, by a locking member (not shown). In this embodiment, the force sensor 1 further includes a bottom cover 50 connected to the bottom surface 12 of the body of the fixing portion 10 and covering the circular arc-shaped lower surfaces 32 of the 2N elastic beams 30. In the present embodiment, the bottom cover 50 includes a bottom cover opening 51 and a plurality of third locking holes 52. The bottom cover opening 51 is spatially opposite to the displacement bottom surface 22 of the force receiving portion 20, so that the force receiving portion 20 does not interfere with the bottom cover 50 when the force receiving portion 20 is displaced downward relative to the fixing portion 10. The third locking holes 52 of the bottom cover 50 are spatially opposite to the first locking holes 13 of the fixing portion 10 and the second locking holes 42 of the top cover 40. The first locking hole 13 and the corresponding second locking hole 42 and third locking hole 52 may be fixed, for example, by a locking member (not shown). In other embodiments, the fixing portion 10 is further fixed to other objects through the upper cover 40 or the bottom cover 50. Of course, the manner in which the upper cover 40 and the bottom cover 50 are fixed to the fixing portion 10 is not limited to the essential features of the present disclosure, and will not be described herein.

Fig. 4 is an enlarged view revealing the region P of fig. 3. Reference is made to fig. 1 to 4. In this embodiment, when the bottom cover 50 is fixed to the bottom surface 12 of the body of the fixing portion 10, and the sensor 1 is fixed to a fixing surface (not shown) through the limiting bottom surface 53 of the bottom cover 50, the limiting bottom surface 53 of the bottom cover 50 is bonded to the fixing surface to form a coplanar surface. In addition, the limiting bottom surface 53 of the bottom cover 50 and the displacement bottom surface 22 of the force receiving portion 20 further form a step structure 60 in a radial direction (parallel to the XY plane), and the step structure 60 has a spacing distance G in an axial direction. In other words, when the sensor 1 is fixed on the fixing surface through the bottom cover 50, the fixing surface further provides a limiting function with respect to the displacement bottom surface 22 of the force receiving portion 20. The spacing distance G is the maximum possible displacement of the deformation of the force-receiving portion 20 in the axial direction. In the present embodiment, when the force receiving portion 20 is displaced toward the bottom cover 50 along the axial direction (i.e. the opposite direction of the Z-axis) by the force F, the force receiving portion 20 has a full-load displacement distance within the step range. For example, when the force sensor is fully loaded with a force of 1 ton, the force receiving portion 20 is displaced downward to generate a full load displacement distance of 0.03mm. In order to avoid damage to the force sensor 1 due to irreversible permanent deformation caused by overload, in this embodiment, the distance G is, for example, 0.06mm, which is 2 times the distance of full load displacement. In other embodiments, the separation distance G is also greater than 2 times the full load displacement distance. In other words, in order to avoid the irreversible permanent deformation of the force sensor 1 and the damage of the material thereof caused by overload, the force sensor 1 further introduces a step structure 60 between the force receiving portion 20 of the elastic body 2 and the bottom cover 50, and makes the spacing distance G greater than or equal to 2 times of the full load deformation distance of the force receiving portion 20, so as to ensure that the force receiving portion 20 of the force sensor 1 is deformed in a certain space. And damage of the force sensor 1 due to deformation of the overload load can be prevented by the support and displacement restriction of the bottom cover 50. On the other hand, the upper cover 40 and the bottom cover 50 are locked to the fixing portion 10 of the elastic body 2, and spatially correspond to the strain gauge 3 fixed to the elastic beam 30. Thus, when the upper cover 40 is locked with the bottom cover 50 and covers the strain gauge 3, it also helps to protect the strain gauge 3 from dirt. Of course, the present disclosure is not limited thereto.

FIG. 5 is a top view of the force sensor of the first embodiment without the cover. FIG. 6 is a functional block diagram of a force sensor according to a first embodiment of the present disclosure. Reference is made to fig. 1 to 6. In the present embodiment, the arrangement of the 4N strain gauges 3 is described with 8 strain gauges 3a to 3h, for example. The 8 strain gauges 3a to 3h are respectively arranged on the 4 elastic beams 30, and are respectively fixed on two opposite side walls of the corresponding elastic beams 30 in pairs. Wherein the strain gauge 3a is connected in series with the strain gauge 3e, the strain gauge 3b is connected in series with the strain gauge 3f, the strain gauge 3c is connected in series with the strain gauge 3g, the strain gauge 3d is connected in series with the strain gauge 3h, and a Wheatstone bridge is formed. Wherein, the 8 strain gauges 3 a-3 h form 4 groups of serial connection, and the resistance value becomes larger after the serial connection. Under the same input voltage, the larger the resistance value, the smaller the current, the thermal influence during electrifying can be reduced, and the measurement accuracy is effectively improved.

In this embodiment, the force sensor 1 further includes a signal processor 4 disposed on the elastic body 3 and electrically connected to the 8 strain gauges 3 a-3 h, and the combination converts an analog signal generated by the strain gauges 3 a-3 h into a digital signal. In the present embodiment, the signal processor 4 includes, for example, an analog-to-digital converter 4a, a digital signal processor 4b, an RS-485 communication interface 4c and a LDO 4d. The signal processor 4 receives a 5V power supply and transmits an input voltage to the voltage input terminal V + V-of the wheatstone bridge formed by the strain gauges 3 a-3 h through the low dropout voltage regulator 4d. Since the strain gauges 3a to 3h etch copper wires on polyimide (polyimide) with high strength and corrosion resistance through a semiconductor process, the copper wires increase or decrease their lengths along with the deformation of the corresponding elastic beams 30, thereby generating resistance changes, so that voltage difference signals s+s-are generated at both ends of the wheatstone bridge.

In this embodiment, when the force F is applied to the force-receiving portion 20 along the axial direction (i.e., the opposite direction of the Z-axis), the elastic beam 30 is driven to deform, so that the strain gauges 3 a-3 h attached to the elastic beam 30 are changed to form, and the wheatstone bridge generates an analog signal output, and then the analog signal is amplified and converted into a digital signal by the analog-digital converter 4a and the digital signal processor 4b in the signal processor 4, and output through the RS-485 communication interface 4c, so as to measure and normalize the force F in the first-order range. As the force F applied to the force sensor 1 increases, the output digital signal also changes proportionally. In this embodiment, the signal processor 4 is disposed inside the force sensor 1 to convert the analog signal into the digital signal at the shortest distance, so that the interference of external noise can be effectively reduced.

FIG. 7 is a top view of a force sensor without a cover according to a second embodiment of the present disclosure. FIG. 8 is a functional block diagram of a force sensor according to a second embodiment of the present disclosure. In the present embodiment, the force sensor 1a is similar to the force sensor 1 shown in fig. 1 to 6, and the same reference numerals refer to the same elements, structures and functions, which are not repeated herein. In the present embodiment, the force sensor 1a includes 2N strain gauges 3 a-3 d respectively disposed on the sidewalls of 2N elastic beams 30, where n=2. The strain gauges 3a and 3b are a pair of strain gauges spatially opposite to each other, and are symmetrically disposed on a single sidewall of the corresponding elastic beam 30. The strain gauges 3c and 3d are a pair of strain gauges spatially opposed to each other and are also symmetrically disposed on a single side wall of the corresponding elastic beam 30. The force sensor 1a performs the function of measuring and normalizing the force F in the primary range by combining the wheatstone bridge formed by the stress transformers 4 a-4 d with the signal processor 4. Of course, in other embodiments, the arrangement of the 2N or 4N strain gauges relative to the 2N elastic beams 30 can be adjusted according to the actual application requirements, and the present utility model is not limited thereto.

In the foregoing embodiment, the stress portion 20 of the elastic body 3 further includes a shaft hole 23 extending through the stress portion 23 along the axial direction. In other embodiments, the object to be measured can be connected to the force receiving portion 20 through the shaft hole 23, so that the force receiving of the force receiving portion 20 is not limited to the top surface 21 of the force receiving portion 20, and the object to be measured can also apply force to the force receiving portion 23 along the axial direction through the shaft hole 23. Of course, the present disclosure is not limited thereto.

FIG. 9 is a schematic diagram showing the dimensions of an elastomer according to a first embodiment of the present disclosure. Reference is made to fig. 1 to 6 and 9. In this embodiment, the elastic body 2 includes 2N elastic beams 30 connected between the fixing portion 10 and the force receiving portion 20, and the force sensor 1 formed by matching with 4N strain gauges 3 can measure and normalize the force applied to the force receiving portion 20 within a specific step range. In this embodiment, n=2, 4 elastic beams 30 have the same shape and size. Wherein each spring beam 30 has a beam width W1 in the XY plane. In addition, each elastic beam 30 also includes a through hole 33 penetrating the circular arc-shaped upper surface 31 and the circular arc-shaped lower surface 32, and the extending direction of the through hole 33 is parallel to the axial direction. Each through hole 33 is located at the center of the elastic beam 30 and has an aperture D1. Where the ratio x of beam width W1 to aperture D1 ranges from 1< ratio x <12. When the ratio x is smaller, e.g., the ratio x is close but greater than 1, the beam width W1 is closer to the value of the aperture D1, i.e., the spring beam 30 is smaller at Liang Hou, such a design may be suitable for measuring smaller force steps, e.g., for a step size of 1 ton for maximum loads. Conversely, when the ratio x is greater, which is representative of a greater beam width W1 than the aperture D1, the larger the spring beam 30 Liang Hou becomes, which is suitable for measuring a greater force step, and this provides the benefit of carrying greater forces through a thicker beam to avoid damage. In other embodiments, the through hole 33 may be replaced by a groove, for example, recessed through the circular arc-shaped upper surface 31 or the circular arc-shaped lower surface 32. The present disclosure is not limited thereto. Therefore, the force sensor 1 formed by assembling the elastic body 2 can realize the function of measuring and normalizing the acting force F in the range of the step distance of 1 ton.

FIG. 10 is a schematic dimensional view of an elastomer according to a second embodiment of the present disclosure. In the present embodiment, the elastomer 2a is similar to the elastomer 2 shown in fig. 9, and like reference numerals refer to like elements, structures and functions, which are not described herein. In the present embodiment, each elastic beam 30 of the elastic body 2a has a beam width W1 in the XY plane. In addition, each elastic beam 30 of the elastic body 2a also includes a through hole 33a penetrating through the circular arc-shaped upper surface 31 and the circular arc-shaped lower surface 32, parallel to the axial direction. Each through hole 33a is located at the center of the elastic beam 30 and has an aperture D2. Where the aperture D2 is larger than the aperture D1 (as shown in fig. 9), the aperture D2< the aperture D1, represents a larger difference between the aperture D2 and the beam width W1, that is, a larger ratio x of the beam width W1 to the aperture D2, in other words, a thicker beam of the elastic beam 30, such a design being applicable to a pitch range of a maximum load of 3 tons, for example. In other embodiments, the through hole 33a may be replaced by a groove, for example, recessed through the circular arc-shaped upper surface 31 or the circular arc-shaped lower surface 32. The present disclosure is not limited thereto. Therefore, the force sensor 1 formed by assembling the elastic body 2a can realize the function of measuring and normalizing the acting force F in the range of 3 tons.

FIG. 11 is a schematic dimensional view of an elastomer according to a third embodiment of the present disclosure. In the present embodiment, the elastomer 2b is similar to the elastomer 2 shown in fig. 9, and like reference numerals refer to like elements, structures and functions, which are not described herein. In the present embodiment, each elastic beam 30 of the elastic body 2b has a beam width W1 in the XY plane. In addition, each elastic beam 30 of the elastic body 2b also includes a through hole 33b penetrating through the circular arc-shaped upper surface 31 and the circular arc-shaped lower surface 32, parallel to the axial direction. Each through hole 33b is located at the center of the elastic beam 30 and has an aperture D3. Where the aperture D3 is larger than the aperture D2 (as shown in fig. 10), the aperture D3< the aperture D2, which means that the difference between the aperture D3 and the beam width W1 is larger, that is, the ratio x of the beam width W1 to the aperture D3 becomes larger. In other words, the thicker the beam of the elastic beam 30 becomes, such a design can be used, for example, to achieve a pitch range of 5 tons at maximum load. In other embodiments, the through hole 33b may be replaced by a groove, for example, recessed through the circular arc-shaped upper surface 31 or the circular arc-shaped lower surface 32. The present disclosure is not limited thereto. Therefore, the force sensor 1 formed by assembling the elastic body 2b can realize the function of measuring and normalizing the acting force F in the range of 5 tons.

FIG. 12 is a schematic dimensional view of an elastomer according to a fourth embodiment of the present disclosure. In the present embodiment, the elastomer 2c is similar to the elastomer 2 shown in fig. 9, and like reference numerals refer to like elements, structures and functions, which are not described herein. In the present embodiment, each elastic beam 30 of the elastic body 2c has a beam width W1 in the XY plane. In this embodiment, each elastic beam 30 of the elastic body 2c is not provided with a through hole or a groove passing through the circular arc-shaped upper surface 31 or the circular arc-shaped lower surface 32. The force sensor 1 formed by assembling the elastic body 2c can realize the function of measuring and normalizing the acting force F in the range of 7.5 tons. Referring to fig. 9 to 12, it can be seen that the force sensor formed by assembling the elastic body 2c can realize the maximum load, for example, the range of 7.5 ton distance, when the groove or the through hole is not started on the elastic beam 30. When the force sensor 1 with the maximum load of 7.5 ton range needs to be adjusted to different step ranges, the elastic body 2c with different beam widths is not needed to be replaced, and only grooves or through holes with different sizes are needed to be formed on the circular arc upper surface 31 or the circular arc lower surface 32 of the elastic beam 30 of the elastic body 2c, for example, the through holes 33, 33a, 33b with the apertures D1, D2, D3 smaller than the beam width W1 can be formed as the elastic bodies 2, 2a, 2b, and the difference between the beam width W1 and the apertures D1, D2, D3 can be proportional to the maximum load of the step ranges of the elastic bodies 2, 2a, 2 b. Furthermore, the resulting elastomer can maintain a resolution of 2mV/V at different step ranges, with the ratio x of beam width to aperture maintained at 1< x <12. Compared with the elastic Liang Liangkuan, the processing procedure of forming the groove or the through hole is simpler. In addition, the load step range is determined by the aperture size of the groove or the through hole, the elastomer can be pre-processed and stored, and the processing procedure of opening the groove or the through hole is performed after the required step range is confirmed, so that the product design has higher flexibility.

FIG. 13 is a schematic dimensional view of an elastomer according to a fifth embodiment of the present disclosure. In the present embodiment, the elastic body 2d is similar to the elastic body 2c shown in fig. 12, and the same reference numerals refer to the same elements, structures and functions, and are not repeated here. In the present embodiment, each elastic beam 30 of the elastic body 2d has a beam width W2 in the XY plane. Compared to the force sensor 1 formed by assembling the elastic body 2c, for example, the force sensor 1 formed by assembling the elastic body 2d has a maximum load range of more than 7.5 tons. In other words, the maximum load step range of the force sensor 1 can be achieved by beam width adjustment of the elastic beam 30. Of course, the present utility model is not limited thereto.

In summary, the present disclosure provides an elastomer and a force sensor suitable for the same. Because the elastic Liang Cai circular arc upper surface and circular arc lower surface that the elastomer provided are designed, when of course the elastomer atress drives the elastic beam and attached strain gauge deformation on it, the elastic beam accessible circular arc upper surface and circular arc lower surface's structure dispersion stress, avoid the excessive concentrated of stress and damage, effectively promote the life of product. The elastic body applicable disc type force sensor can be used for measuring the load acting force in a primary distance range and simultaneously avoiding damage of the force sensor caused by irreversible permanent deformation generated by overload load. In order to avoid irreversible permanent deformation and material damage of the force sensor caused by overload, the force sensor also introduces a step structure between the displacement bottom surface of the stress part of the elastic body and the limit bottom surface of the bottom cover, and the spacing distance formed by the step structure is more than or equal to 2 times of the full-load deformation distance of the stress part. When the force sensor is fixed on a fixing surface through the bottom cover, the fixing surface enables the stress part of the force sensor to deform in a certain space. The force sensor can be prevented from being damaged due to overload deformation under the action of supporting and limiting displacement by the fixing surface fixed by the bottom cover. In addition, the upper cover and the bottom cover are locked on the fixing part of the elastic body and also correspond to the strain gauge fixed on the elastic beam in space, so that when the upper cover and the bottom cover are locked and cover the strain gauge, the strain gauge is further protected from being polluted by dust. In addition, the maximum load stage distance range of the force sensor can be adjusted through the beam width of the elastic beam. When the force sensor needs to be adjusted to different step ranges, the elastic body with different elastic beam widths does not need to be replaced, and only the arc-shaped upper surface or the arc-shaped lower surface of the elastic beam is provided with grooves or through holes with different sizes, and the resolution of 2mV/V can be maintained under different step ranges. Compared with the elastic Liang Liangkuan, the processing procedure of forming the groove or the through hole is simpler. In addition, the load step range is determined by the aperture size of the groove or the through hole, the elastomer can be pre-processed and stored, and the processing procedure of opening the groove or the through hole is performed after the required step range is confirmed, so that the product design has higher flexibility.

The present utility model is modified in this way by a person skilled in the art without departing from the scope of protection as claimed in the appended claims.

Claims (10)

1. A force sensor, comprising:

the elastic body comprises a fixed part, a stress part and 2N elastic beams, N is an integer and is more than or equal to 1, the fixed part is arranged around the outer periphery of the stress part in a surrounding way, the 2N elastic beams are symmetrically arranged and connected between the stress part and the fixed part, wherein each elastic beam is provided with an arc-shaped upper surface, and the arc-shaped upper surface is connected between the top surface of the stress part and the top surface of the fixed part; and

at least 2N strain gauges spatially corresponding to the 2N elastic beams, each strain gauge being disposed on a side wall of the corresponding elastic beam, wherein when an acting force is applied to the stress portion along an axial direction, the stress portion drives the 2N elastic beams and the 2N strain gauges to change shape, so as to measure the acting force within a range of a first distance, and reduce a maximum stress value generated by the acting force through the circular arc-shaped upper surface.

2. The force sensor of claim 1, wherein each of the elastic beams has a circular arc-shaped bottom surface connected between a displacement bottom surface of the force-bearing portion and a bottom surface of the body of the fixing portion.

3. The force sensor of claim 2, comprising a bottom cover connected to a bottom surface of the body of the fixing portion and covering the circular arc lower surfaces of the 2N elastic beams, wherein a limiting bottom surface of the bottom cover and a displacement bottom surface of the force receiving portion further form a stepped structure in a radial direction.

4. The force sensor of claim 3, wherein the force receiving portion has a full-load displacement distance within the step size range when the force receiving portion is displaced toward the bottom cover in the axial direction by the force, and the step structure has a spacing distance in the axial direction, wherein the spacing distance is greater than or equal to 2 times the full-load displacement distance.

5. The force sensor of claim 1, comprising a signal processor disposed on the elastomer and electrically connected to the at least 2N strain gauges, the assembly converting an analog signal generated by the 2N strain gauges into a digital signal.

6. The force sensor of claim 2, wherein each of the 2N spring beams includes a recess recessed through the circular arc upper surface or the circular arc lower surface.

7. The force sensor of claim 6, wherein each of the 2N spring beams has a beam width, a ratio of the beam width to an aperture of the groove is x, and x ranges from 1< x <12.

8. The force sensor of claim 2, wherein each of the 2N spring beams includes a through hole extending through the circular arc upper surface and the circular arc lower surface and parallel to the axial direction.

9. The force sensor of claim 8, wherein each of the 2N spring beams has a beam width, a ratio of the beam width to the aperture of the through hole is x, and x ranges from 1< x <12.

10. The force sensor of claim 1, wherein the at least 2N strain gauges comprise 4N strain gauges, the 4N strain gauges being disposed on two opposite sidewalls of the 2N spring beams, respectively.

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