Zero adjustment for load cells and load cells

Abstract

The application provides a zero position adjusting part for a load sensor and the load sensor, and relates to the technical field of sensors. The zero position adjusting part comprises an adjusting seat and an operating part. The adjusting seat is provided with a cavity for accommodating a pull shaft of the load sensor. A first displacement adjusting structure is arranged on the outer wall of the adjusting seat. The first displacement adjusting structure cooperates with a second displacement adjusting structure arranged on the inner wall of the shell of the load sensor to adjust the displacement of the adjusting seat in the extension direction of the pull shaft. The operating part is arranged on the adjusting seat and surrounds the adjusting seat. A user can operate the zero position adjusting part to rotate so as to adjust the displacement of the adjusting seat in the extension direction of the pull shaft. The zero position adjusting part is used to make the load sensor have the function of peeling zero adjustment, and the measurement accuracy of the load sensor is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sensors, in particular to a zero position adjusting piece for a load cell and the load cell. BACKGROUND

[0002] Most load cells adopt a particularly thick elastic body as a carrier of a resistance strain gauge, so that the elastic body bears external force received by the load cell and generates a counterforce to the external force, so as to achieve balance. In this process, a strain field is generated on the surface of the elastic body, so that the resistance strain gauge pasted on the surface of the elastic body completes the conversion from strain to electrical signal, and finally realizes the function of weighing. The load cell needs to be zeroed before use, and the existing zeroing mechanism is relatively complex. SUMMARY

[0003] Therefore, the present application provides a zero position adjusting piece for a load cell and the load cell, which can solve the above technical problems.

[0004] In a first aspect, the present application provides a zero position adjusting piece for a load cell, which comprises an adjusting seat and an operation part. The adjusting seat is provided with a cavity for accommodating a pull shaft of the load cell, and a first displacement adjusting structure is arranged on the outer wall of the adjusting seat. The first displacement adjusting structure cooperates with a second displacement adjusting structure arranged on the inner wall of the shell of the load cell, and is used to adjust the displacement of the adjusting seat in the extension direction of the pull shaft. The operation part is arranged on the adjusting seat and surrounds the adjusting seat, and is used by a user to rotate the zero position adjusting piece to adjust the displacement of the adjusting seat in the extension direction of the pull shaft. A first groove recessed towards the side where the operation part is located is arranged on the inner wall of the adjusting seat and surrounds the pull shaft, and is used to accommodate a load bearing member sleeved on the pull shaft.

[0005] In an embodiment, the size of the cross section of the first groove is greater than the size of the cross section of the cavity, so as to form a first step structure on the inner wall of the adjusting seat, which is used to abut against the load bearing member.

[0006] In an embodiment, a second groove extending towards the side where the operation part is located is arranged on the outer wall of the other end of the adjusting seat, so as to form a first limiting step on the outer wall of the adjusting seat. The first limiting step cooperates with a second limiting step on the shell, and is used to limit the displacement of the zero position adjusting piece in the direction towards the load bearing member.

[0007] In an embodiment, the adjusting seat is cylindrical, and the second groove is a circular ring arranged along the outer wall of the adjusting seat.

[0008] In an embodiment, the adjusting seat is cylindrical, and the first displacement adjusting structure is a thread distributed along the circumference of the cylindrical shape.

[0009] In one embodiment, the first groove is annular, and the cavity is cylindrical.

[0010] In one embodiment, the outer wall of the operating part is formed with at least two contact surfaces for cooperating with an object clamped by the operating part.

[0011] In one embodiment, the at least two contact surfaces include six contact surfaces.

[0012] The second aspect of the present application also provides a load cell, which comprises a housing, a pull shaft, an elastic sheet, a load carrier and the zero adjustment member of any of the above embodiments, wherein the housing is a hollow cavity provided with an opening; the pull shaft comprises a free end and a connecting end, wherein the connecting end is arranged in the hollow cavity, the free end extends out of the opening and protrudes from the housing, and the pull shaft is movable in the axial direction relative to the hollow cavity; the elastic sheet is arranged in the hollow cavity and can be deformed with the movement of the pull shaft; and the load carrier is arranged in the hollow cavity and located between the free end and the connecting end, and under the action of an external force applied to the free end, the load carrier is compressed under stress, and the pull shaft moves and drives the elastic sheet to deform.

[0013] According to the technical solution of the present application, the zero adjustment member can apply a pre-tightening force to the load carrier with elasticity, and the size of the pre-tightening force can be adjusted, wherein the load carrier is arranged in the housing of the load cell, and this design enables the load cell to have the function of skin removal zero adjustment, thereby improving the measurement accuracy of the load cell. At the same time, the load carrier is arranged on the pull shaft, and after the pull shaft is stressed, the load carrier becomes the main stressed component instead of the elastic sheet, thereby improving the service life of the elastic sheet and solving the problem of the influence of the elastic body on the service life and measurement accuracy of the load cell in the previous improved scheme. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 Fig. 1 shows a cross-sectional view of a zero adjustment member for a load cell according to an embodiment of the present application.

[0015] Figure 2 Fig. 2 shows a structural schematic diagram of a load cell according to an embodiment of the present application.

[0016] Figure 3 Fig. 3 shows a cross-sectional view of a load cell according to an embodiment of the present application.

[0017] 1 - zero adjustment member; 11 - adjustment seat; 12 - operating part; 2 - pull shaft; 21 - free end; 22 - connecting end; 3 - housing; 4 - load carrier; 5 - first groove; 6 - second groove; 7 - elastic sheet. DETAILED DESCRIPTION

[0018] With reference to the drawings and embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application.

[0019] The load cell mainly comprises a shell, a pull shaft, an elastic sheet provided with strain gauges, and the like. One end of the pull shaft is connected with the elastic sheet, and the other end is used for connecting a load to be weighed. One end of the elastic sheet is connected with the shell, and the other end is connected with the pull shaft. When the load is connected on the pull shaft, the pull shaft drives the elastic sheet to deform, so that the weight of the load can be obtained according to the change of the resistance measured by the strain gauges on the elastic sheet. Since the elastic sheet is the force receiving element mainly receiving the external force on the pull shaft in the load cell, the elastic sheet needs a certain thickness to ensure the rigidity requirement, and the thicker elastic sheet will produce creep after long time use, thereby affecting the service life and the accuracy of the load cell.

[0020] The load cell further comprises a load bearing member with elasticity. The embodiments of the present application provide a zero adjustment member for the load cell, so that the load cell with the structure can be zeroed to improve the measurement accuracy of the load cell. Meanwhile, after the pull shaft is stressed, the load bearing member serves as the main stressed component, so that the elastic body can be made thin to form the elastic sheet. At this time, the elastic sheet is not easy to produce creep, thereby improving the service life of the elastic sheet and the measurement accuracy of the load cell.

[0021] Figure 1 Fig. 1 is a sectional view of the zero adjustment member for the load cell provided by an embodiment of the present application.

[0022] The zero adjustment member 1 comprises an adjustment seat 11 and an operation part 12. The adjustment seat 11 is provided with a cavity for accommodating the pull shaft 2 of the load cell, and the outer wall of the adjustment seat 11 is provided with a first displacement adjustment structure. The first displacement adjustment structure cooperates with a second displacement adjustment structure provided on the inner wall of the shell 3 of the load cell, and is used for adjusting the displacement of the adjustment seat 11 in the extension direction of the pull shaft 2. The operation part 12 is arranged around the adjustment seat 11 and is used for rotating the zero adjustment member 1 by a user to adjust the displacement of the adjustment seat 11 in the extension direction of the pull shaft 2. The inner wall of the adjustment seat 11 is provided with a first groove 5 recessed to the side where the operation part 12 is arranged around the pull shaft 2, and is used for accommodating the load bearing member 4 sleeved on the pull shaft 2.

[0023] Specifically, the operation part 12 is arranged at one end of the adjusting seat 11, and the first groove 5 is arranged at the other end of the adjusting seat 11. The zero position adjusting piece 1 is assembled between the pull shaft 2 and the shell 3. First, the zero position adjusting piece 1 is sleeved on the pull shaft 2, that is, the pull shaft 2 is arranged in the adjusting seat 11 of the zero position adjusting piece 1. Then, through the rotation operation of the operation part 12 by the user, the first displacement adjusting structure on the zero position adjusting piece 1 cooperates with the second adjusting structure on the shell 3, so that the zero position adjusting piece 1 moves relative to the pull shaft 2 and the shell 3 in the direction of the load bearing piece 4. At this time, the load bearing piece 4 limited in the first groove 5 is compressed and starts to deform. After stopping the rotation operation, the zero position adjusting piece 1 stops moving and is fixed on the shell 3 through the cooperation of the first displacement adjusting structure and the second displacement adjusting structure. At this time, the load bearing piece 4 limited in the first groove 5 stops deforming, and the load bearing piece 4 is applied with a pre-tightening force.

[0024] The zero position adjusting piece 1 provided by the embodiment of the present application adjusts the size of the pre-tightening force applied to the load bearing piece 4 by adjusting the displacement of the zero position adjusting piece 1 relative to the shell 3 and the pull shaft 2, so as to adjust the "dead zone" weight. This effect can make the load applied to the load cell achieve the effect of "peeling zero" by adjusting the pre-tightening force of the load bearing piece 4. In addition, the first groove limits the stress end of the load bearing piece 4, improves the stability of the deformation of the load bearing piece 4 during the stress process, and further improves the measurement accuracy of the load cell. At the same time, the load bearing piece 4 replaces the elastic sheet 7 as the main force receiving part, reduces the risk of creep of the elastic sheet 7, and improves the service life and measurement accuracy of the load cell.

[0025] In one embodiment, the size of the cross section of the first groove 5 is greater than the size of the cross section of the cavity, so as to form a first step structure on the inner wall of the adjusting seat 11, which is used to abut against the load bearing piece 4.

[0026] Specifically, the other end of the load bearing piece 4 is directly abutted in the first step structure, so that the abutted end face of the load bearing piece 4 directly contacts the connecting face of the first groove 5 and the cavity, so that the load bearing piece 4 is clamped in the first adjusting structure. Therefore, during the compression process of the load bearing piece 4, the abutted end of the load bearing piece 4 does not move relative to the zero position adjusting piece 1, which further improves the stability of the deformation of the load bearing piece 4. After the zero position adjusting piece 1 stops moving, the abutted end of the load bearing piece 4 also does not move relative to the zero position adjusting piece 1, which improves the stability of the pre-tightening force on the load bearing piece 4, and thus improves the measurement accuracy of the load cell.

[0027] In an alternative embodiment, the load carrier 4 is a disc spring assembly, and the first groove 5 is a spring seat structure. This scheme not only has a simple structure, but also facilitates production and processing, and reduces production costs. More importantly, by using the small range and large force characteristics of the disc spring assembly, the measurement range of the load sensor is improved without making major changes to the existing size of the asymmetric load sensor.

[0028] In an embodiment, the outer wall of the other end of the adjusting seat 11 is provided with a second groove 6 extending to the side where the operating part 12 is located, so as to form a first limiting step on the outer wall of the adjusting seat 11. The first limiting step cooperates with the second limiting step on the shell 3 to limit the displacement of the zero adjustment piece 1 in the direction of the load carrier 4.

[0029] In this embodiment, the cooperation of the first limiting step and the second limiting step limits the maximum pre-tightening force applied by the zero adjustment piece 1 to the load carrier 4, avoiding the problem of affecting the service life of the load carrier 4 due to too large pre-tightening force applied to the load carrier 4 parts, and improving the service life of the load sensor.

[0030] In an embodiment, the adjusting seat 11 is cylindrical, and the second groove 6 is a circular ring arranged along the outer wall of the adjusting seat 11. This structure facilitates processing and saves production costs.

[0031] In an embodiment, the adjusting seat 11 is cylindrical, and the first displacement adjusting structure is a thread distributed along the circumference of the cylinder. This structure not only optimizes the product structure, but also facilitates processing and saves production costs.

[0032] Specifically, the first displacement adjusting structure is an external thread arranged on the outer wall of the adjusting seat 11, and the second displacement adjusting structure is an internal thread arranged on the inner wall of the shell 3 of the load sensor. The cooperation of the internal and external threads enables the zero adjustment piece 1 to adjust the size of the pre-tightening force applied to the load carrier 4. This structure design is simple, easy to implement, and saves production costs.

[0033] It can be understood that the above embodiment only provides a specific scheme for realizing the adjusting function of the zero adjustment piece 1, but is not limited to the above scheme. Other technical schemes can also be used, for example, an internal thread is arranged on the inner wall of the adjusting seat 11, and an external thread is arranged on the outer surface of the pull shaft 2 in contact with the adjusting seat 11. The cooperation of the above internal and external threads realizes the adjustment of the pre-tightening force size of the load carrier 4 by the zero adjustment piece 1. It should be understood that appropriate technical schemes can be selected according to the specific structure of the load sensor and other conditional factors.

[0034] In one embodiment, the first groove 5 is circular ring-shaped, and the cavity is cylindrical. The circular ring-shaped first groove 5 is adapted to the cross-sectional shape of the load carrier 4, and the circular ring is more uniformly stressed, and the load carrier 4 is more stably limited, thereby improving the accuracy of the load sensor. Meanwhile, the structure of the cavity is adapted to the structure of the pull shaft 2, thereby reducing the friction between the zero position adjusting member 1 and the pull shaft 2 when the zero position adjusting member 1 moves relative to the pull shaft 2, and improving the working efficiency of the zero position adjusting member 1 in adjusting the pre-tightening force on the load carrier 4. It can be understood that the structure of the cavity can be designed according to the specific structure of the pull shaft 2.

[0035] In one embodiment, at least two contact surfaces are formed on the outer wall of the operation part 12, and the contact surfaces are used to cooperate with the object clamped by the operation part 12. The design of the contact surface facilitates the adjustment operation of the operator, and not only can be manually operated, but also can be operated by clamping the contact surface by means of an operation tool, thereby improving the working efficiency.

[0036] It can be understood that the design of the operation surface is not limited to the above, and other technical solutions can also be used to improve the working efficiency of the zero position adjusting member, for example, a "cross" type operation groove is designed on the end surface of the operation part 12 away from the load carrier 4, and a cross screwdriver or a multifunctional screwdriver can be used to realize the adjustment of the zero position adjusting member 1, thereby improving the working efficiency.

[0037] In one embodiment, the at least two contact surfaces include six contact surfaces. Similar to the structure of a six-sided nut, the existing operation tool can be used to adjust the zero position adjusting member 1, and a special adjusting tool does not need to be designed, thereby saving production cost. It can be understood that the designer can determine the number of contact surfaces according to specific needs, and the number is not limited to the number provided in the embodiment.

[0038] Figure 2 A structure schematic diagram of the load sensor provided in one embodiment of the present application is shown. Figure 3 A cross-sectional view of the load sensor provided in one embodiment of the present application is shown.

[0039] The load sensor includes a housing 3, a pull shaft 2, an elastic sheet 7, a load carrier 4, and the zero position adjusting member 1 of any one of the above embodiments, wherein the housing 3 is a hollow cavity 11 with an opening; the pull shaft 2 includes a free end 21 and a connecting end 22, and the free end 21 and the connecting end 22 are connected, wherein the connecting end 22 is arranged in the hollow cavity 11, the free end 21 protrudes out of the opening and protrudes from the housing 3, and the pull shaft 2 can move along the axial direction relative to the hollow cavity 11; the elastic sheet 7 is arranged in the hollow cavity 11 and can be deformed along with the movement of the pull shaft 2; the load carrier 4 is arranged in the hollow cavity 11 and located between the free end 21 and the connecting end 22, and under the action of an external force applied to the free end 21, the load carrier 4 is compressed by force, and at the same time, the pull shaft 2 moves and drives the elastic sheet 7 to move and deform.

[0040] In one embodiment, the adjusting seat 11 of the zero position adjusting member 1 is in an integral structure with the shell 3, which increases the strength of the overall structure of the load sensor, facilitates the machining and production of the parts, and saves production costs.

[0041] The load sensor of the embodiment of the present application realizes the adjustment of the pre-tightening force on the load bearing member 4 through the zero position adjusting member 1, so that the sensor has the function of peeling and zero adjustment. At the same time, the design of the load bearing member 4 and the elastic sheet 7 also solves the problem that the thick elastic body will produce creep after being stressed for a long time, thereby affecting the service life and the measurement accuracy of the load sensor.

[0042] In the description of the present specification, the description referring to the terms "one embodiment", "some embodiments", "example", and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the present application herein only for the purpose of describing specific embodiments and is not intended to limit the present application. The term "and / or" used herein includes any and all combinations of one or more of the associated listed items.

[0044] In addition, the terms "first", "second", etc. are only used for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can include at least one of the features, either explicitly or implicitly.

[0045] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A zero-point adjustment component for a weighing sensor, characterized in that, include: The adjusting seat has a cavity for accommodating the pull shaft of the weighing sensor, and a first displacement adjusting structure is provided on the outer wall of the adjusting seat. The first displacement adjusting structure cooperates with a second displacement adjusting structure provided on the inner wall of the housing of the weighing sensor to adjust the magnitude of the displacement of the adjusting seat in the extension direction of the pull shaft. An operating unit is disposed on and surrounding the adjusting seat, allowing the user to rotate the zero-position adjusting member to adjust the displacement of the adjusting seat in the extension direction of the pull shaft. The inner wall of the adjusting seat is provided with a first groove recessed towards the side where the operating part is located around the pull shaft, for accommodating a load-bearing member that is sleeved on the pull shaft and has elasticity.

2. The zero-position adjustment component according to claim 1, characterized in that, The cross-sectional dimension of the first groove is larger than the cross-sectional dimension of the cavity, so as to form a first step structure on the inner wall of the adjusting seat for abutting against the load-bearing member.

3. The zero-position adjustment component according to claim 1, characterized in that, A second groove extending toward the side where the operating part is located is provided on the outer wall of the other end of the adjustment seat to form a first limiting step on the outer wall of the adjustment seat. The first limiting step cooperates with the second limiting step on the housing to limit the magnitude of the displacement of the zero-position adjustment member toward the load-bearing member.

4. The zero-position adjustment component according to claim 3, characterized in that, The adjusting seat is cylindrical, and the second groove is a ring arranged along the outer wall of the adjusting seat.

5. The zero-position adjustment component according to claim 1, characterized in that, The adjusting seat is cylindrical, and the first displacement adjusting structure is a thread distributed along the circumference of the cylinder.

6. The zero-position adjustment component according to claim 1, characterized in that, The first groove is annular, and the cavity is cylindrical.

7. The zero-position adjustment element according to any one of claims 1-6, characterized in that, At least two contact surfaces are formed on the outer wall of the operating part, and the contact surfaces are used to cooperate with the object that holds the operating part.

8. The zero-position adjustment member according to claim 7, characterized in that, The at least two contact surfaces include six contact surfaces.

9. A weighing sensor, characterized in that, include: The shell is a hollow cavity with an opening; A pull shaft includes a free end and a connecting end, wherein the connecting end is disposed in the hollow cavity, the free end extends out of the opening and protrudes from the housing, and the pull shaft is axially movable relative to the hollow cavity; An elastic sheet is disposed within the hollow cavity and can deform as the pull shaft moves; A load-bearing component is disposed in the hollow cavity and located between the free end and the connecting end. Under the action of an external force applied to the free end, the load-bearing component is compressed, and at the same time, the pull shaft moves and drives the elastic sheet to move and deform. The zero-position adjustment element according to any one of claims 1-8.

Images