A locking structure applied to a load cell and a load cell

Abstract

The application provides a locking structure applied to a load sensor and the load sensor, and relates to the technical field of sensors. The locking structure comprises a shell, a load adjusting part and a locking part. The shell is a hollow cavity with an opening at the top, used for accommodating a pull shaft of the load sensor. A load bearing part of the load sensor and an elastic sheet sleeve of the load sensor are arranged on the pull shaft, and the elastic sheet is arranged on the shell. The load bearing part is limited between the opening and the elastic sheet, used for bearing the pulling force borne by the pull shaft. The cavity between the opening and the load bearing part is a mounting cavity of the hollow cavity. One end of the load adjusting part is arranged in the mounting cavity and is in contact with the load bearing part, used for adjusting the size of the pre-tightening force on the load bearing part. The locking part is used for connecting the load adjusting part and the shell, and is used for locking the relative position between the load adjusting part and the shell. The application solves the problem of unstable pre-tightening force on the elastic part in the load sensor.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sensors, in particular to a locking structure applied to a load cell and the load cell. BACKGROUND

[0002] A load cell is a device that converts a mass signal into a measurable electrical signal output. There are various types of load cells, and a strain gauge load cell measures weight by using the principle that the resistance of an electric resistance strain gauge changes when it deforms. When a pre-tightening force is used to achieve the skin removal zeroing function of a load cell, the size of the pre-tightening force is unstable, and is easily affected by external vibrations or other conditions, so that the skin removal zeroing of the load cell is also inaccurate, thereby affecting the measurement accuracy of the load cell. SUMMARY

[0003] Therefore, the present application provides a locking structure applied to a load cell and the load cell, which can solve the above technical problems.

[0004] In a first aspect, the present application provides a locking structure applied to a load cell, which comprises a housing, a load adjusting member and a locking member. The housing is a hollow cavity provided with an opening, and is used to accommodate a pull shaft of the load cell. One end of the pull shaft is arranged in the hollow cavity, and the other end of the pull shaft is arranged outside the opening. A load bearing member of the load cell and an elastic sheet of the load cell are sleeved on the pull shaft, and the elastic sheet is arranged on the housing. The load bearing member is limited between the opening and the elastic sheet, and is used to bear the pulling force of the pull shaft. The cavity between the opening and the load bearing member is an installation cavity of the hollow cavity. One end of the load adjusting member is arranged in the installation cavity and is in contact with the load bearing member, and is used to adjust the size of the pre-tightening force on the load bearing member. The locking member is used to connect the load adjusting member and the housing, and is used to lock the relative position between the load adjusting member and the housing.

[0005] In one embodiment, the other end of the load adjusting member protrudes outside the opening, and the cross-sectional area of the other end of the load adjusting member is greater than the cross-sectional area of the installation cavity. In the extension direction of the pull shaft, the locking member connects the other end of the load adjusting member and the installation cavity.

[0006] In one embodiment, the installation cavity is cylindrical, and the load adjusting member comprises a rod portion with a cylindrical cross-section and a cap portion with a cylindrical cross-section connected to the rod portion. The outer diameter of the rod portion is smaller than the inner diameter of the installation cavity, and the outer diameter of the cap portion is greater than the inner diameter of the installation cavity.

[0007] In one embodiment, there is a gap between the end surface of the cap portion facing the load bearing member and the end surface of the installation cavity away from the load bearing member.

[0008] In one embodiment, the size of the gap decreases with the increase of the length of the rod portion extending into the mounting cavity, and is negatively related to the size of the pre-tightening force on the load carrier.

[0009] In one embodiment, the locking member is a locking bolt, and the other end of the load adjusting member is provided with a through hole matched with the locking bolt, and the mounting cavity is correspondingly provided with a threaded hole matched with the through hole and the locking bolt.

[0010] In one embodiment, the threaded hole is provided with a plurality of.

[0011] In one embodiment, the through hole is provided with a plurality of, and the plurality of through holes are symmetrically distributed on the other end of the load adjusting member, and the plurality of threaded holes are symmetrically distributed on the mounting cavity, and the plurality of threads correspond one-to-one to the plurality of through holes.

[0012] In one embodiment, the number of locking bolts is three, and the locking bolts are uniformly distributed relative to the central axis of the hollow cavity.

[0013] The second aspect of the present application also provides a load cell, which comprises the locking structure for the load cell according to any one of the above.

[0014] According to the technical solution of the present application, by arranging the locking member between the shell and the load adjusting member, the problem of reduced measurement accuracy of the load cell caused by unstable pre-tightening force applied on the load carrier is solved. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 Fig. 1 shows a structure schematic diagram of a locking structure for a load cell provided by an embodiment of the present application.

[0016] Figure 2 Fig. 2 shows a top view of the locking structure for the load cell provided by the embodiment of the present application.

[0017] Figure 3 Fig. 3 shows a cross-sectional view of the load cell provided by the embodiment of the present application.

[0018] 1-shell; 11-mounting cavity; 2-load adjusting member; 3-locking member; 31-through hole; 32-threaded hole; 33-locking bolt; 4-load carrier; 5-pull shaft; 51-free end; 52-connection end; 6-elastic sheet. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments.

[0020] The load cell mainly comprises a shell, a pull shaft, an elastic sheet provided with strain gauges and other elements. 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 to 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 bearing element mainly bearing 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 accuracy of the load cell.

[0021] In order to improve the service life and accuracy of the load cell, the embodiments of the present application also design a load bearing member with elasticity for bearing most of the external force applied to the pull shaft, so that a thinner elastic sheet can be used to measure the weight. In order to set the load bearing member in the shell to make it the main force bearing element, the embodiments of the present application also use a load adjusting member to apply a pre-tightening force to the load bearing member, and take the state of the load bearing member at this time as its initial state. However, due to transportation or other circumstances, the load adjusting member may be displaced, thereby changing the size of the pre-tightening force on the load bearing member, which is not conducive to the structural stability of the load cell and affects the service life or use effect, for example, the measurement accuracy of the load cell.

[0022] Figure 1 Fig. 1 shows a structure schematic diagram of a locking structure applied to a load cell according to an embodiment of the present application. Figure 2 Fig. 2 shows a top view of the locking structure applied to the load cell according to an embodiment of the present application.

[0023] The locking structure comprises a shell 1, a load adjusting member 2 and a locking member 3. The shell 1 is a hollow cavity provided with an opening, used for accommodating a pull shaft 5 of the load cell. One end of the pull shaft 5 is arranged in the hollow cavity, used for connecting with an elastic sheet 6 of the load cell. The other end of the pull shaft 5 is arranged outside the opening, used for connecting a load. A load bearing member 4 and the elastic sheet 6 of the load cell are sleeved on the pull shaft 5, and the elastic sheet 6 is arranged on the shell 1. The load bearing member 4 is limited between the opening and the elastic sheet 6, used for bearing the tension of the pull shaft 5. The cavity between the opening and the load bearing member 4 is an installation cavity 11 of the hollow cavity. One end (also referred to as the first end) of the load adjusting member 2 is arranged in the installation cavity 11 and in contact with the load bearing member 4, used for adjusting the size of the pre-tightening force on the load bearing member 4. The locking member 3 is used for connecting the load adjusting member 2 and the shell 1, used for locking the relative position between the load adjusting member 2 and the shell 1.

[0024] The locking member 3 connects the load adjusting member 2 and the housing 1, and increases the firmness of the connection between the two, which can be understood as making the pre-tightening force exerted by the load adjusting member 2 on the load bearing member 4 more stable, and solving the problem of unstable pre-tightening force on the elastic load bearing member 4 affecting the measurement accuracy of the load sensor.

[0025] Specifically, the connection between the load adjusting member 2 and the housing 1 is regarded as a whole, and the technical solution can be designed from multiple angles to strengthen the stability of the overall structure, such as designing the technical solution from the side of the overall structure, the direction from the bottom to the top of the overall structure, the direction from the top to the bottom of the overall structure, or the circumferential direction of the overall structure, or even starting from the inside of the overall structure, such as the technical solution of adding the locking member 3 between the load adjusting member 2 and the housing 1 to increase the connection strength between the load adjusting member 2 and the housing 1.

[0026] It should be understood that when designing the structure of the locking member 3, in addition to considering the locking effect that the locking member 3 can achieve, the difficulty of the related scheme of the locking member 3 and the production cost of applying the locking structure to the load sensor should also be considered. In the embodiment of the present application, a technical solution of designing the locking member 3 from the top to the bottom of the overall structure is provided.

[0027] In one embodiment, the other end (also referred to as the second end) of the load adjusting member 2 protrudes outside the opening, and the cross-sectional area of the second end of the load adjusting member 2 is greater than the cross-sectional area of the mounting cavity 11; in the extension direction of the pull shaft 5, the locking member 3 connects the second end of the load adjusting member 2 and the mounting cavity 11. The design of the load adjusting member 2 not only facilitates the assembly between the load adjusting member 2 and the housing 1, but also facilitates the insertion of the locking member 3 into the side wall of the mounting cavity 11 corresponding to the load bearing member 4 in the direction from the second end of the load adjusting member 2 to the first end of the load adjusting member 2 without affecting the strength of the overall structure. The technical solution is simple and easy to implement.

[0028] In one embodiment, the mounting cavity 11 is cylindrical, the load adjusting member 2 includes a cylindrical rod portion and a cylindrical cap portion connected to the rod portion, the outer diameter of the rod portion is smaller than the inner diameter of the mounting cavity 11, and the outer diameter of the cap portion is greater than the inner diameter of the mounting cavity. This structure design is not only convenient for production and processing, but also facilitates the assembly between the load adjusting member 2 and the mounting cavity 11, and saves production cost.

[0029] In one embodiment, there is a gap between the end face of the cap portion facing the load bearing member 4 and the end face of the mounting cavity away from the load bearing member 4. Of course, the gap can also not be provided. The design of the gap takes into account the error that may exist during the processing of parts, reduces the precision requirement of part processing, and saves production cost.

[0030] In one embodiment, the size of the gap decreases with the increase of the length of the rod portion extending into the mounting cavity, and is negatively related to the size of the pre-tightening force on the load carrier 4. By adjusting the size of the gap, the length of the rod portion of the load adjusting member 2 extending into the mounting cavity 11 is actually adjusted, and in turn the size of the pre-tightening force applied to the load carrier 4 is adjusted, thereby increasing the adaptability of the structure.

[0031] In one embodiment, the locking member 3 is a locking bolt 33, and the second end (i.e. the cap portion) of the load adjusting member 2 is provided with a through hole 31 matched with the locking bolt 33, and the mounting cavity 11 is correspondingly provided with a threaded hole 32 matched with the through hole 31 and the locking bolt 33. The embodiment of the present application fastens the load adjusting member by matching the locking bolt with the threaded hole 32, so that the fastening mode of the load adjusting member is simple and easy to implement, and cost is saved.

[0032] In one embodiment, the threaded hole 32 is provided with a plurality of threaded holes, and a plurality of locking bolts 33 are used to lock the load adjusting member 2 and the housing 1 in multiple dimensions. Moreover, this scheme includes multiple cases, i.e. one threaded hole corresponds to one through hole, multiple threaded holes correspond to multiple through holes, or a combination of the above two cases, which can be designed according to the actual production and processing needs.

[0033] Specifically, the plurality of through holes 31 are symmetrically distributed on the second end of the load adjusting member 2, the threaded hole 32 is provided with a plurality of threaded holes, and the plurality of threaded holes 32 are symmetrically distributed on the mounting cavity 11. The plurality of threaded holes 32 correspond to the plurality of through holes 31 one by one. Under the premise of ensuring the overall structural strength, the locking effect of the locking member 3 between the housing 1 and the load adjusting member 2 is improved.

[0034] Specifically, the number of locking bolts is 3, and they are uniformly distributed relative to the central axis of the hollow cavity. This structure is not only convenient for processing, but also makes each part of the housing and the load adjusting member bear force uniformly, thereby improving the locking effect without affecting the service life of the parts.

[0035] Figure 3 Fig. 1 shows a cross-sectional view of a load cell provided by an embodiment of the present application.

[0036] The load cell comprises the locking structure for the load cell according to any one of the above embodiments.

[0037] The load cell of the above scheme further comprises a shell 1, a pull shaft 5, an elastic sheet 6, a load bearing 4 and a load adjusting member 2, wherein the shell 1 is a hollow cavity provided with a first opening; the pull shaft 5 comprises a free end 51 and a connecting end 52 connected together, wherein the connecting end 52 is arranged in the hollow cavity, the free end 51 extends out of the first opening and protrudes from the shell 1, and the pull shaft 5 is axially movable relative to the hollow cavity; the elastic sheet 6 is arranged in the hollow cavity and can be deformed with the movement of the pull shaft 5; the load bearing 4 is arranged in the hollow cavity and located between the free end 51 and the connecting end 52, under the effective force of an external force applied to the free end 51, the load bearing 4 is compressed under stress, at the same time, the pull shaft 5 moves and drives the elastic sheet 6 to deform; wherein the effective force is a component of the external force in a direction parallel to the direction in which the pull shaft 5 extends; the load adjusting member 2 is arranged at the first opening and sleeved on the outer periphery of the pull shaft 5, and cooperates with the shell 1 to adjust the size of the pre-tightening force applied to the load bearing 4.

[0038] In the description of the present specification, the description of 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 mean 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.

[0039] 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 be limiting of the present application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0040] In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated, so that the features limited by "first", "second" can be explicitly or implicitly included at least one feature.

[0041] 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 locking structure for use in a weighing sensor, characterized in that, include: The housing is a hollow cavity with an opening for accommodating the pull shaft of the load cell. One end of the pull shaft is disposed in the hollow cavity for connecting to the elastic plate of the load cell, and the other end of the pull shaft is placed outside the opening for connecting a load. The load-bearing component of the load cell and the elastic plate are sleeved on the pull shaft, and the elastic plate is disposed on the housing. The load-bearing component is confined between the opening and the elastic plate for bearing the tensile force on the pull shaft, and the cavity between the opening and the load-bearing component is the mounting cavity of the hollow cavity. A load adjustment component, one end of which is disposed in the mounting cavity and contacts the load bearing component, for adjusting the magnitude of the preload force on the load bearing component; A locking element is used to connect the load adjusting element and the housing, and to lock the relative position between the load adjusting element and the housing; The other end of the load adjusting member protrudes outside the opening, and the cross-sectional area of ​​the other end of the load adjusting member is larger than the cross-sectional area of ​​the mounting cavity. In the extending direction of the pull shaft, the locking member connects the other end of the load adjusting member to the mounting cavity.

2. The locking structure according to claim 1, characterized in that, The mounting cavity is cylindrical, and the load adjusting member includes a rod with a cylindrical cross-section and a cap with a cylindrical cross-section connected to the rod; the outer diameter of the rod is smaller than the inner diameter of the mounting cavity, and the outer diameter of the cap is larger than the inner diameter of the mounting cavity.

3. The locking structure according to claim 2, characterized in that, There is a gap between the end face of the cap facing the load-bearing member and the end face of the mounting cavity away from the load-bearing member.

4. The locking structure according to claim 3, characterized in that, The size of the gap decreases as the length of the rod extending into the mounting cavity increases, and is negatively correlated with the magnitude of the preload on the load-bearing member.

5. The locking structure according to claim 1, characterized in that, The locking component is a locking bolt, and the other end of the load adjusting component is provided with a through hole that mates with the locking bolt. The mounting cavity is correspondingly provided with a threaded hole that mates with the through hole and the locking bolt.

6. The locking structure according to claim 5, characterized in that, The threaded holes are provided in multiple ways.

7. The locking structure according to claim 6, characterized in that, Multiple through holes are provided, and the multiple through holes are symmetrically distributed on the other end of the load adjusting member. Multiple threaded holes are symmetrically distributed on the mounting cavity, and the multiple threads correspond one-to-one with the multiple through holes.

8. The locking structure according to claim 5, characterized in that, There are three locking bolts, and the locking bolts are evenly distributed around the central axis of the hollow cavity.

9. A weighing sensor, characterized in that: Includes the locking structure for a weighing sensor as described in any one of claims 1-8.

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