A load cell

Abstract

The application provides a kind of load cell, it relates to the technical field of sensor, the load cell includes shell, pull shaft, elastic sheet and load carrier, wherein load carrier is arranged in hollow cavity and is located between free end and connecting end, under the effective force of external force applied to free end, load carrier is compressed under stress, while pull shaft body moves and drives elastic sheet to move to produce deformation, wherein effective force is the component of external force in the direction parallel to the direction of pull shaft body extension. Load carrier is used as the main component to bear external force, which avoids elastic sheet directly under stress and prolongs the service life of elastic sheet.

Description

TECHNICAL FIELD

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

[0002] The load cell generally adopts a particularly thick elastic body as a carrier of a resistance strain gauge, so that the elastic body bears the external force borne by the load cell and generates a reaction force to the external force, thereby achieving 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 elastic body is a thick alloy steel sheet, which is a main force receiving component and is prone to plastic deformation. Meanwhile, in the range of its scale, the elastic body also has a relatively large creep after being subjected to force for a long time, thereby causing inaccurate weighing.

[0003] Therefore, there is an urgent need to provide a new solution to solve the problem of reduced service life and reduced accuracy caused by deformation of the elastic body in the load cell. SUMMARY

[0004] Therefore, the embodiments of the present application provide a load cell, which replaces the elastic body with a load bearing member as a main force receiving component, thereby solving the problem of affecting the service life and accuracy of the load cell caused by long-term force on the elastic body.

[0005] In a first aspect, the present application provides a load cell, which comprises a shell, a pull shaft, an elastic sheet and a load bearing member. The shell comprises a hollow cavity provided with a first opening. The pull shaft comprises a pull shaft body, one end of the pull shaft body being a free end and the other end of the pull shaft body being a connecting end. The connecting end is arranged in the hollow cavity, and the pull shaft body can move along the axial direction relative to the hollow cavity. The elastic sheet is arranged in the hollow cavity and can be deformed along with the movement of the pull shaft body. The load bearing member is arranged in the hollow cavity and located between the free end and the connecting end. Under the effective action of an external force applied to the free end, the load bearing member is compressed by force, and the pull shaft body moves and drives the elastic sheet to deform. The effective action is the component of the external force in the direction parallel to the direction in which the pull shaft body extends.

[0006] In an embodiment, the hollow cavity is sequentially formed with a first limiting cavity and a second limiting cavity in the direction towards the first opening. The first limiting cavity is relatively far away from the first opening, and the minimum cross-sectional area of the first limiting cavity is greater than the maximum cross-sectional area of the second limiting cavity, so as to limit the displacement of the reciprocating movement of the pull shaft body. The second limiting cavity is arranged between the first limiting cavity and the first opening, and is used to limit the load bearing member between the first opening and the elastic sheet.

[0007] In one embodiment, the load carrier is a disc spring assembly, comprising a plurality of disc spring group units, wherein each disc spring group unit comprises a first single disc spring and a second single disc spring, wherein the first single disc spring has a first tapered structure, and the top of the first tapered structure is provided with a first mounting hole; the second single disc spring has a second tapered structure, and the top of the second tapered structure is provided with a second mounting hole; the first single disc spring is located below the second single disc spring, and the top of the first tapered structure and the top of the second tapered structure are fitted together; the first single disc spring and the second single disc spring are coaxially sleeved on the pull shaft body through the first mounting hole and the second mounting hole, respectively.

[0008] In one embodiment, the load sensor further comprises a load adjusting member, which is arranged at the first opening and sleeved on the outer periphery of the pull shaft body, for adjusting the size of the pre-tightening force applied to the load carrier, wherein the end of the load carrier away from the first opening is fixed relative to the pull shaft, and the end of the load carrier close to the first opening is in contact with the first end face of the load adjusting member away from the first opening.

[0009] In one embodiment, the load adjusting member extends into the second limiting cavity, and the first end face is provided with a limiting structure for limiting the end of the load carrier close to the first opening on the load adjusting member.

[0010] In one embodiment, a mounting cavity is further formed between the second limiting cavity and the first opening in the hollow cavity, and the load adjusting member extends into the second limiting cavity through the mounting cavity, wherein a first displacement adjusting structure is arranged on the inner wall of the mounting cavity, and a second displacement adjusting structure is correspondingly arranged on the outer wall of the load adjusting member, the first displacement adjusting structure and the second displacement adjusting structure cooperate to fix the load adjusting member in the mounting cavity and adjust the length of the load adjusting member extending into the second limiting cavity.

[0011] In one embodiment, the load sensor further comprises a locking device, a mounting cavity is further formed between the second limiting cavity and the first opening in the hollow cavity, the load adjusting member extends into the second limiting cavity through the mounting cavity, and the locking device is arranged outside the mounting cavity to reinforce the connection between the load adjusting member and the shell by reducing the inner diameter of the mounting cavity.

[0012] In one embodiment, the inner wall of the mounting cavity is parallel to the inner wall of the second limiting cavity, the outer wall of the mounting cavity forms an angle γ with the outer wall of the second limiting cavity, and 0°<γ<90°.

[0013] In one embodiment, the locking device comprises a locking body and a third displacement adjusting structure, the locking body is a cavity, comprising a connecting part for connecting the outer wall of the second limiting cavity and a pressing part for pressing the outer wall of the installation cavity, wherein the inner wall of the connecting part and the inner wall of the pressing part form an included angle δ, and δ≥γ; the third displacement adjusting structure is arranged on the inner wall of the connecting part and cooperates with the fourth displacement adjusting structure arranged on the outer wall of the installation cavity to adjust the displacement of the connecting part relative to the second limiting cavity.

[0014] In one embodiment, a fine slot extending from the installation cavity to the first opening is arranged in the direction in which the pull shaft body extends, starting from the position where the second limiting cavity is close to the installation cavity.

[0015] In one embodiment, the locking device comprises a locking bolt, which cooperates with the through hole arranged on the load adjusting member and the threaded hole arranged on the shell and communicating with the through hole.

[0016] In one embodiment, the load cell further comprises a zero position platform, the connecting end is arranged on the zero position platform and can reciprocate relative to the zero position platform in the direction in which the zero position platform faces the first opening; the elastic sheet is arranged on the connecting end and deforms with the reciprocation, and when the connecting end is stationary on the zero position platform, the elastic sheet is in the initial deformation state.

[0017] In one embodiment, the zero position platform comprises a platform body and an installation platform, wherein the platform body is provided with a hollow cavity in the direction in which the pull shaft body extends; the installation platform is protruded on the inner wall of the hollow cavity, the installation platform is provided with a third mounting hole with an opening facing the first opening, and the third mounting hole is used for assembling the elastic sheet on the installation platform; when the elastic sheet is in the same horizontal plane as the installation platform, the elastic sheet is always in the initial deformation state.

[0018] In one embodiment, the zero position platform further comprises a cover arranged in the cavity, the cover is provided with an assembly slot for assembling the connecting end in the direction in which the pull shaft body extends, and the height of the cover is lower than the height of the installation platform in the direction in which the pull shaft body extends.

[0019] In one embodiment, the pull shaft body further comprises a top shaft, the top shaft is used for detachably assembling with the connecting end of the pull shaft, and the top shaft is configured to be movably assembled in the cover, and when the top shaft is stationary relative to the cover, the elastic sheet is simultaneously in the initial deformation state.

[0020] In one embodiment, the load cell further comprises a radial limiting structure arranged between the pull shaft and the hollow cavity, which is used for limiting the movement of the pull shaft body relative to the shell in the radial direction of the pull shaft body.

[0021] In one embodiment, the assembly groove of the cover is provided with a bottom surface away from one end of the first opening, and the radial limiting structure comprises a first sleeve and / or a second sleeve, wherein the first sleeve is sleeved on the pull shaft body and close to the free end; and the second sleeve is sleeved between the top shaft and the cover.

[0022] In one embodiment, the assembly groove of the cover is a through groove, and the radial limiting structure comprises a mounting groove and a flexible rubber sheet, wherein the mounting groove is arranged in the circumferential direction of the outer surface of the pull shaft body, and the plane where the mounting groove is located is perpendicular to the extension direction of the pull shaft body; and the flexible rubber sheet is clamped in the mounting groove and forms an interference fit with the inner wall of the hollow cavity.

[0023] In one embodiment, a third limiting structure is arranged on the pull shaft body close to the connecting end, and the third limiting structure is located in the first limiting cavity and can only reciprocate in the first limiting cavity.

[0024] In one embodiment, the third limiting structure is a boss arranged in the circumferential direction of the outer wall of the pull shaft body, and the boss is provided with a notch, and the notch is adapted to the shape of a mounting platform provided on the inner wall of the hollow cavity for assembling the elastic sheet, and when the notch cooperates with the mounting platform, the elastic sheet is in an initial deformation state.

[0025] In one embodiment, the connecting line of the notch of the mounting platform and the boss is a non-straight line.

[0026] In one embodiment, the elastic sheet comprises a mounting arm and an extension arm, and the elastic sheet is an integrally formed sheet structure that spirally extends outward from the mounting arm to the extension arm, wherein one of the mounting arm and the extension arm is provided with a first mounting structure for assembling the elastic sheet on the shell, and the other is provided with a second mounting structure for mounting the elastic sheet on the connecting end, so that when the connecting end moves relative to the shell in the elastic force direction of the elastic sheet, the mounting arm elastically moves relative to the extension arm.

[0027] In one embodiment, the elastic sheet further comprises a connecting arm connecting the mounting arm and the extension arm, and the rotation angle of one end of the connecting arm to the other end of the connecting arm is β, and 0°<β<360°.

[0028] In one embodiment, at least one first assembly hole is arranged on the extension arm, and a fastener passes through the first assembly hole and a second assembly hole arranged on the shell to assemble the elastic sheet on the shell.

[0029] In one embodiment, a gasket is further arranged on the end face of the extension arm facing the force applying end of the fastener.

[0030] In one embodiment, at least one positioning hole is further arranged on the extension arm, and the positioning hole cooperates with a positioning column arranged on the shell to limit the elastic sheet on the shell.

[0031] In one embodiment, the thickness of the elastic sheet is 0.3-0.5mm.

[0032] The application provides a load sensor, which sets a load carrier between the pull rod and the elastic sheet to bear the external force of most of the free end of the pull rod, avoids the elastic sheet from being directly stressed, and solves the problem that the elastic sheet is stressed too much or frequently stressed, thereby affecting the service life or causing creep to affect the measurement accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 An exploded view of the load sensor provided by one embodiment of the application is shown.

[0034] Figure 2 An exploded view of the load sensor provided by one embodiment of the application is shown.

[0035] Figure 3 A structural schematic view of the load sensor provided by one embodiment of the application is shown.

[0036] Figure 4 A partial structural schematic view of the load sensor provided by one embodiment of the application is shown.

[0037] Figure 5 A structural schematic view of the load sensor provided by one embodiment of the application is shown.

[0038] Figure 6 A sectional view of the load sensor provided by one embodiment of the application is shown.

[0039] Figure 7 A sectional view of the load sensor provided by one embodiment of the application is shown.

[0040] Figure 8 A top view of the load sensor provided by one embodiment of the application is shown.

[0041] Figure 9 A partial structural schematic view of the load sensor provided by one embodiment of the application is shown.

[0042] Figure 10 A structural schematic view of the elastic sheet provided by one embodiment of the application is shown.

[0043] Figure 11 A structural schematic view of the elastic sheet provided by one embodiment of the application is shown.

[0044] Figure 12 A structural schematic view of the elastic sheet provided by one embodiment of the application is shown.

[0045] Figure 13 A structural schematic view of the elastic sheet provided by one embodiment of the application is shown.

[0046] Figure 14 Fig. 1 is a structural schematic diagram of a housing of a load sensor according to an embodiment of the present application.

[0047] Figure 15 Fig. 2 is a sectional view of the housing of the load sensor according to an embodiment of the present application.

[0048] 1 - housing; 11 - first opening; 12 - slot; 13 - zero position platform; 131 - platform body; 132 - mounting platform; 133 - second assembly hole; 134 - cover; 135 - positioning column; 14 - threaded hole; 15 - mounting cavity; 16 - second limiting step; 17 - first limiting cavity; 18 - second limiting cavity;

[0049] 2 - pull shaft; 21 - free end; 22 - connecting end; 23 - third limiting structure; 231 - notch; 24 - top shaft; 25 - limiting protrusion;

[0050] 3 - elastic sheet; 31 - mounting arm; 32 - connecting arm; 321 - first vertical arm; 322 - first horizontal arm; 323 - second vertical arm; 324 - third vertical arm; 325 - second horizontal arm; 326 - third horizontal arm; 33 - extension arm; 331 - first assembly hole; 332 - positioning hole; 34 - fourth mounting hole;

[0051] 4 - load carrier; 41 - first single disc spring; 411 - first tapered structure; 412 - first mounting hole; 42 - second single disc spring; 421 - second tapered structure; 422 - second mounting hole;

[0052] 5 - load adjusting member; 51 - limiting groove; 52 - through hole; 53 - first limiting step; 54 - first end face;

[0053] 6 - locking device; 61 - pressing part; 62 - connecting part;

[0054] 71 - first sleeve; 72 - second sleeve; 731 - first mounting groove; 732 - second mounting groove; 74 - flexible rubber sheet; 8 - gasket. DETAILED DESCRIPTION

[0055] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments.

[0056] Figure 1 Fig. 1 is a structural schematic diagram of a housing of a load sensor according to an embodiment of the present application. Figure 2 Fig. 1 is a structural schematic diagram of a housing of a load sensor according to an embodiment of the present application.

[0057] The weighing sensor comprises a shell 1, a pull shaft 2, an elastic sheet 3, a strain sheet and a load carrier 4, wherein the shell 1 comprises a hollow cavity provided with a first opening 11; the pull shaft 2 comprises a pull shaft body, one end of the pull shaft body is a free end 21, and the other end of the pull shaft body is a connecting end 22, wherein the connecting end 22 is arranged in the hollow cavity, and the pull shaft body can move axially relative to the hollow cavity. The elastic sheet 3 is arranged in the hollow cavity and will be deformed with the movement of the pull shaft body. The load carrier 4 is arranged in the hollow cavity and located between the free end 21 and the connecting end 22. Under the effective force of the external force applied to the free end 21, the load carrier 4 is compressed under stress, while the pull shaft body moves and drives the elastic sheet 3 to move and deform; wherein the effective force is the component of the external force in the direction parallel to the direction in which the pull shaft body extends.

[0058] According to the embodiments of the present application, the load carrier 4 is used as the main component to bear the external force, avoiding the elastic sheet 3 directly bearing the force, thereby prolonging the service life of the elastic sheet 3. At the same time, the elastic sheet 3 deforms under the action of the pull shaft 2 and gradually disappears with the disappearance of the external force, which, together with the load carrier 4, achieves the technical effects of improving the service life and precision of the weighing sensor.

[0059] Specifically, the free end 21 of the pull shaft 2 can be connected to a load or a machine body. For example, when the free end 21 of the pull shaft 2 is connected to the object to be weighed, the weight of the object to be weighed is taken as the load, the pull shaft body is pulled to move axially, at this time, the load carrier 4 is compressed as the main force-bearing component, while the force applied by the load on the elastic sheet 3 is small or even zero, and the elastic sheet 3 is driven by the movement of the pull shaft body to elastically deform and generate a strain field, and then outputs a signal through the strain sheet attached to the elastic sheet 3, thereby measuring the weight of the object to be weighed.

[0060] There are various ways to connect the free end 21 to the weight of the object to be weighed. In an optional embodiment, the free end 21 protrudes out of the first opening 11 and beyond the shell 1, which facilitates the connection between the free end 21 and the object to be weighed, thereby improving the work efficiency. In order to further improve the efficiency of the process, the end of the free end 21 protruding out of the shell 1 can be designed in a circular ring shape or a hook shape, and a hook or other small parts can be used to quickly connect the object to be weighed to the hook. It should be understood that the protruding length of the free end and the structure of the part protruding from the free end 21 can be specifically designed according to the structure of the product and actual needs, and are not limited to the technical solutions provided above.

[0061] It can be understood that the shell in the above embodiment can include other decorative components for decorating the appearance of the load sensor or mounting components for suspending the load sensor on a plane for the use of products. In addition, the hollow cavity can further include a second opening arranged opposite to the first opening at the bottom of the hollow cavity, that is, the hollow cavity can be made into a through cavity to facilitate the production and assembly of the parts inside the hollow cavity. The top of the hollow cavity refers to the direction of the free end 21 of the pull shaft 2 protruding, and the bottom of the hollow cavity refers to the direction opposite to the free end 21.

[0062] The elastic sheet 3 can be made thin to have greater elasticity while achieving a larger stroke and not prone to creep. In an embodiment, the thickness of the elastic sheet 3 is 0.3-0.5 mm. Under the premise of ensuring the service life and accuracy of the load sensor, the load sensor has a larger range, solving the problem of short stroke and large creep caused by the relatively thick elastic sheet 3 in the traditional load sensor.

[0063] There are various schemes for the assembly relationship between the structures of the parts for realizing the functions of the load sensor, such as Figure 15 As shown in the figure, in an embodiment, the hollow cavity sequentially forms a first limiting cavity 17 and a second limiting cavity 18 in the direction of the first opening 11, wherein the first limiting cavity 17 is relatively far from the first opening 11, and the minimum cross-sectional area of the first limiting cavity 17 is greater than the maximum cross-sectional area of the second limiting cavity 18, for limiting the displacement size of the reciprocating movement of the pull shaft body; the second limiting cavity 18 is arranged between the first limiting cavity 17 and the first opening 11, for limiting the load carrier 4 between the first opening 11 and the elastic sheet 3.

[0064] Specifically, the first limiting cavity 17 is respectively provided with a second opening and a third opening at two ends, and the second cavity 18 is respectively provided with a fourth opening and a fifth opening at two ends, wherein the second opening is away from the first opening 11, the third opening of the first limiting cavity 17 is communicated with the third opening of the second limiting cavity 18, and the fourth opening of the second limiting cavity 18 is communicated with the first opening 11, wherein the size relationship of the cross-sectional areas between the first limiting cavity 17 and the second limiting cavity 18 is limited, and finally the load carrier 4 is limited between the first opening 11 and the connecting end 22, and then it is limited between the load and the elastic sheet 3, which plays a role of replacing the elastic sheet 3 to bear most of the force. Specifically, the first limiting cavity 17 and the second limiting cavity 18 are both uniform cylindrical cavities, which facilitates the processing of the shell 1 and the assembly between the parts later.

[0065] As Figures 1-2As shown, in one embodiment, the load-bearing component 4 is a disc spring assembly, which includes multiple disc spring units. Each disc spring unit includes a first single-piece disc spring 41 and a second single-piece disc spring 42. The first single-piece disc spring 41 has a cross-sectional structure of a first conical structure 411, and the top of the first conical structure 411 is provided with a first mounting hole 412. The second single-piece disc spring 42 has a cross-sectional structure of a second conical structure 421, and the top of the second conical structure 421 is provided with a second mounting hole 422. The first single-piece disc spring 41 is located below the second single-piece disc spring 42, and the tops of the first conical structure 411 and the second conical structure 421 are aligned. The first single-piece disc spring 41 and the second single-piece disc spring 42 are coaxially sleeved on the pull shaft body through the first mounting hole 412 and the second mounting hole 422, respectively.

[0066] The weighing sensor in the above embodiment utilizes the characteristics of disc springs, which have high load capacity, short stroke, and are not prone to creep. By combining multiple sets of first single disc springs 41 and second single disc springs 42 to form a load-bearing component 4, it can become a suitable force-bearing component. While improving the lifespan of the weighing sensor, it also increases the weighing range of the weighing sensor without significantly affecting the size of the weighing sensor.

[0067] In one embodiment, the first single-piece disc spring 41 and the second single-piece disc spring 42 are respectively positioned on the pull shaft body. This improves the stability of the disc spring assembly unit structure, thereby enhancing the measurement accuracy of the load cell. Specifically, soft adhesive can be used to fix the first single-piece disc spring 41 and the second single-piece disc spring 42 to the pull shaft body. When the disc spring assembly unit is not under load or under light load, the structure between the first single-piece disc spring 41 and the second single-piece disc spring 42 remains unchanged, preventing misalignment and improving the stability of the structure.

[0068] It should be understood that the disc spring assembly can be selected with appropriate parameters and combinations based on the technical requirements, operating conditions, and load stroke of the load cell. In another embodiment, the first single-piece disc spring 41 and the second single-piece disc spring 42 in the disc spring assembly are disc springs with an outer diameter D = 20 mm, an inner diameter d = 10.2 mm, a thickness t = 0.8 mm, a height h = 1.35 mm, and made of 60Si2Mn material, respectively, and are combined in pairs of eight. The embodiments of this application are not limited to disc spring assemblies, and other elastic load-bearing components, such as spring assemblies or other parts made of highly elastic materials, can be selected according to the actual needs of the product.

[0069] like Figures 2-4As shown, the weighing sensor in the above embodiment may further include a load adjusting member 5. This load adjusting member 5 is disposed at the first opening 11 and sleeved on the outer periphery of the pull shaft body, and is used to adjust the magnitude of the preload applied to the load bearing member 4. The end of the load bearing member 4 away from the first opening 11 is fixed relative to the pull shaft 2, and the end of the load bearing member 4 near the first opening 11 contacts the first end face 54 of the load adjusting member 5 away from the first opening 11. By adjusting the magnitude of the preload of the load bearing member 4, the weighing sensor can achieve the function of tare zeroing.

[0070] like Figure 4 As shown, in one embodiment, the load adjustment member 5 extends into the second limiting cavity, and a limiting structure is provided on the first end face 54 to limit the end of the load bearing member 4 facing the first opening 11 on the load adjustment member 5. This design can prevent the load bearing member 4 from deforming in other directions when subjected to force during operation.

[0071] In one embodiment, the limiting structure is a limiting groove 51 that is recessed in the direction of the first end face 54 toward the first opening 11. It should be understood that the formation of the limiting groove 51 can be selected according to the actual process. It can be formed by the first end face 54 being recessed in the direction of the first opening 11, or by the periphery of the first end face 54 extending in the direction of the first opening 11 to form a convex surface, or other methods. No further restrictions are imposed here.

[0072] It is understood that the above embodiment is only one implementation of the limiting structure, but the limiting of the deformation direction of the load-bearing member 4 is not limited to this solution. For example, other limiting structures can be used, such as U-shaped slots, cross-shaped slots, or other shapes of buckles. It should be understood that the limiting structure is only one way to limit the load-bearing member 4 and the load adjusting member 5. In practical applications, the design scheme can be selected according to one's own choices.

[0073] like Figures 6-7 As shown, in one embodiment, an installation cavity is also formed in the hollow cavity between the second limiting cavity and the first opening 11. The load adjustment member 5 extends into the second limiting cavity through the installation cavity. The inner wall of the installation cavity is provided with a first displacement adjustment structure, and the outer wall of the load adjustment member 5 is correspondingly provided with a second displacement adjustment structure. The first displacement adjustment structure and the second displacement adjustment structure cooperate to fix the load adjustment member 5 in the installation cavity and adjust the length of the load adjustment member 5 extending into the second limiting cavity.

[0074] Specifically, after adjusting the length of the load adjusting member 5 extending into the second limiting cavity, the load bearing member 4 installed in the limiting structure, i.e. the limiting groove 51 on the first end surface 54 of the load adjusting member 5, will be compressed or elongated in the direction of the extension of the pull shaft body, i.e. the pre-tightening force of the load bearing member 4 in the direction of the extension of the pull shaft body is adjusted, thereby playing a role of adjusting the "dead zone" weight. This role 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 member 4.

[0075] In one embodiment, the cavity of the mounting cavity is cylindrical, the first displacement adjusting structure is a first mounting thread circumferentially distributed on the inner wall of the mounting cavity, and the second displacement adjusting structure is a second mounting thread matched with the first mounting thread and arranged on the outer wall of the load adjusting member 5.

[0076] Specifically, the load adjusting member 5 is an adjusting bolt with threads, the first mounting thread and the second mounting thread are fine threads, the adjusting bolt is connected with the shell 1 through the fine threads, and the load bearing member 4 is assembled in the second limiting cavity and located between the adjusting bolt and the pull shaft 2. By screwing the adjusting bolt, the adjusting bolt is radially displaced along the extension direction of the pull shaft body, so that the load bearing member 4 is pressed downward to the connecting end 22. However, the connecting end 22 does not displace along the extension direction of the pull shaft body, so that the load bearing member 4, i.e. the disc spring assembly, has a pre-tightening force at this time. When the external force pulling the free end 21 exceeds the pre-tightening force of the disc spring assembly, the free end 21 will drive the elastic sheet 3 at the connecting end 22 to displace along the extension direction of the pull shaft body. Therefore, the screwing length of the adjusting bolt represents the size of the pre-tightening force of the disc spring assembly, thereby playing a role of adjusting the "dead zone" weight. Further, the load applied to the load cell can achieve the effect of "peeling zero" by adjusting the pre-tightening force of the disc spring assembly.

[0077] In one embodiment, the load adjusting member 5 is provided with a first limiting step 53 away from the first opening 11, the end surface of the first limiting step 53 faces away from the first opening 11, and the inner wall of the hollow cavity is provided with a second limiting step 16 with an end surface facing the first opening 11. The first limiting step 53 and the second limiting step 16 cooperate to limit the maximum displacement of the axial movement of the load adjusting member 5, i.e. the maximum pre-tightening force that can be applied to the load bearing member 4 is adjusted, thereby preventing the problem of excessive pre-tightening force of the load bearing member 4 affecting the service life.

[0078] After the load adjusting member 5, i.e. the adjusting bolt, is screwed into the shell 1, the length of the adjusting bolt screwed into the shell 1 will be affected by external factors such as vibration, i.e. the stability of the pre-tightening force of the disc spring assembly is affected, thereby affecting the accuracy of the measurement of the load cell. Therefore, in order to increase the stability of the load cell during use, the load adjusting member 5 is provided with a first limiting step 53 away from the first opening 11, the end surface of the first limiting step 53 faces away from the first opening 11, and the inner wall of the hollow cavity is provided with a second limiting step 16 with an end surface facing the first opening 11. The first limiting step 53 and the second limiting step 16 cooperate to limit the maximum displacement of the axial movement of the load adjusting member 5, i.e. the maximum pre-tightening force that can be applied to the load bearing member 4 is adjusted, thereby preventing the problem of excessive pre-tightening force of the load bearing member 4 affecting the service life. Figures 1-7The load adjusting member 5 is inserted into the second limiting cavity through the mounting cavity, and the locking device 6 is arranged outside the mounting cavity 15 to tighten the hollow cavity to reinforce the connection between the load adjusting member 5 and the shell 1.

[0079] The load adjusting member 5 is inserted into the second limiting cavity through the mounting cavity, and the locking device 6 is arranged outside the mounting cavity 15 to tighten the hollow cavity to reinforce the connection between the load adjusting member 5 and the shell 1.

[0080] In one embodiment, the inner wall of the mounting cavity 15 is parallel to the inner wall of the second limiting cavity, and the outer wall of the mounting cavity 15 forms an angle γ with the outer wall of the second limiting cavity, and 0°<γ<90°. The outer wall of the mounting cavity 15 is designed to have an acute angle inclined towards the center of the mounting cavity 15, which is beneficial to the tightening of the mounting cavity 15.

[0081] In an alternative embodiment, 0°<γ≤10°, which makes the tightening of the mounting cavity 15 easy and improves the work efficiency without affecting the strength of the mounting cavity 15 and the assembly of parts.

[0082] As to the specific structure design of the locking device 6, as shown in Figure 1 、 Figure 3 、 Figure 6 In one embodiment, the locking device 6 includes a locking body and a third displacement adjusting structure, wherein the locking body is a hollow cavity including a connecting part 62 for connecting the outer wall of the second limiting cavity and a pressing part 61 for pressing the outer wall of the mounting cavity, and the inner wall of the connecting part 62 forms an angle δ with the inner wall of the pressing part 61, and δ≥γ; the third displacement adjusting structure is arranged on the inner wall of the connecting part 62 and cooperates with the fourth displacement adjusting structure arranged on the outer wall of the mounting cavity 15 to adjust the displacement of the connecting part 62 relative to the second limiting cavity.

[0083] Specifically, under the cooperation of the third displacement adjusting structure and the fourth displacement adjusting structure, the locking main body moves downward relative to the second limiting cavity, and since δ≥γ, the pressing portion 61 of the locking device presses against the outer wall of the mounting cavity 15, and during the downward movement of the connecting portion 62, an outward force is applied to the mounting cavity 15, so that the outer wall of the mounting cavity 15 moves toward the center of the mounting cavity 15, thereby achieving the effect of tightening the mounting cavity 15. It can be understood that when the connecting portion 62 moves upward relative to the second limiting cavity, i.e., moves toward the direction close to the pressing portion 61 until it is separated from the second limiting cavity, the pressure applied by the pressing portion 61 to the outer wall of the mounting cavity 15 disappears, and the tightening of the mounting cavity 15 is released.

[0084] In the above embodiment, the locking device 6 directly uses the wall surface of the pressing portion 61 as a force applying structure without any additional design, thereby saving production cost and improving production efficiency.

[0085] As shown in Figure 4 , Figure 6 In one embodiment, δ=γ, so that the inner wall of the pressing portion 61 is attached to the outer wall of the mounting cavity 15, which not only serves as a guide to facilitate the relative movement between the locking device 6 and the shell 1, but also maximizes the force receiving area between the pressing portion 61 and the mounting cavity 15, thereby improving the working efficiency of the tightened mounting cavity 15. It should be understood that due to the allowable error between the processing techniques, δ≈γ in actual production process.

[0086] In one embodiment, the third displacement adjusting structure is a screw thread provided on the inner wall of the connecting portion 62, and the fourth displacement adjusting structure is a corresponding external screw thread provided on the outer wall of the second limiting cavity, and the inner and outer screw threads cooperate to adjust the displacement of the connecting portion relative to the second limiting cavity.

[0087] Specifically, the second limiting cavity is cylindrical, and the corresponding cavity of the connecting portion 62 of the locking main body is also cylindrical. The locking main body is sleeved on the outer wall of the second limiting cavity, and the relative movement between the two is achieved through the screw thread. This not only simplifies the structure and facilitates the processing, but also facilitates the execution of the locking work and improves the working efficiency.

[0088] As shown in Figure 4As shown, in one embodiment, in the direction in which the pull shaft body extends, a second limiting cavity is arranged close to the position of the mounting cavity 15, and a thin groove 12 is arranged extending from the mounting cavity 15 to the first opening 11, that is, the end of the thin groove 12 away from the first opening 11 is closed, and the end close to the first opening 11 is open. The design of the thin groove 12 is designed to make the shell 1 easy to deform, so as to facilitate the tightening of the shell 1 when the locking body is assembled with the shell 1, thereby playing a role in locking the load adjusting device, and further improving the locking efficiency. In an alternative embodiment, a plurality of thin grooves 12 are arranged on the outer peripheral wall of the shell 1 and are evenly distributed in the circumferential direction.

[0089] In an alternative embodiment, the same thin groove 12 is arranged on the first part of the second limiting cavity and the second part arranged on the mounting cavity 15, forming an included angle equal to the included angle γ formed by the outer wall of the mounting cavity 15 and the outer wall of the second limiting cavity. This design is to maximize the performance of the shell 1 being locked under the premise of minimizing the impact of the thin groove 12 on the strength of the shell 1, and the design of the thin groove 12 also facilitates processing and production, improving work efficiency.

[0090] In one embodiment, in the direction in which the pull shaft body extends, the length of the thin groove 12 in the second limiting cavity is less than the length of the fourth displacement adjusting structure, that is, the outer thread, that is, there is a complete outer thread on the second limiting cavity. This design improves the working efficiency of tightening the mounting cavity 15 while not affecting the moving speed of the locking device 6 relative to the second limiting cavity.

[0091] It should be understood that there are many ways to improve the stability of the pre-tightening force on the load carrier 4, and in the present embodiment, the use of the locking device 6 to fix the load adjusting member 5 and the shell 1 is used, but the locking device 6 is not limited to the above-mentioned scheme. For example, Figure 2 、 Figure 7 As shown in another embodiment, the locking device 6 includes a locking bolt, which cooperates with the through hole 52 arranged on the load adjusting member 5 and the threaded hole 14 arranged on the shell 1 and communicating with the through hole 52.

[0092] According to the embodiment of the present application, the load adjusting member 5 and the shell 1 are fixed together directly through the locking bolt, realizing the fastening of the two, so as to prevent the load adjusting member 5 from being affected during vibration, improve the stability of the size of the pre-tightening force on the load carrier 4, and further improve the measurement accuracy of the load sensor.

[0093] In an alternative embodiment, the cavity of the shell is cylindrical, the locking bolts are multiple, the through holes 52 are multiple, the threaded holes 14 are multiple, and the multiple through holes 52 and the multiple threaded holes 14 are respectively symmetrically distributed around the central axis of the pull shaft body, thereby improving the stability of the overall structure of the load adjusting member 5. It should be understood that the distribution of the locking bolts is directly related to the structure of the shell 1 and the load adjusting member 5, and can be specifically designed according to the shapes of the two.

[0094] It can be understood that the above embodiments only give two schemes for enhancing the connection strength between the load adjusting member 5 and the shell 1, but are not limited to the above two schemes. Other ways can also be used, for example, based on the fact that the mounting cavity 15 itself has a certain contraction ability, the locking device 6 is wrapped on the outer wall of the mounting cavity to form multiple locking blades, and the gap between the locking blades relative to the locking device 6 itself can be adjusted. The tightening of the mounting cavity can also be achieved in the process of reducing the gap.

[0095] In an embodiment, the load sensor further comprises a zero position platform 13, the connecting end 22 is arranged on the zero position platform 13 and can reciprocate relative to the zero position platform 13 in a direction in which the zero position platform 13 faces the first opening 11; the elastic sheet 3 is arranged on the connecting end 22 and deforms with the reciprocation, and when the connecting end 22 is stationary on the zero position platform 13, the elastic sheet 3 is in an initial deformation state.

[0096] Specifically, the zero position of the load sensor refers to the position at which the elastic sheet 3 of the structure does not deform, at which time the load sensor is at zero position. In use, in order to improve the convenience of use of the load sensor and facilitate comparison of different weights of objects, the user needs to adjust the load sensor to zero position before use. Therefore, the zero position is an important parameter for the load sensor. Regarding the zero position platform 13 designed in the present application, it is a platform position of the initial deformation state of the elastic sheet 3.

[0097] It can be understood that the initial deformation state of the elastic sheet 3 refers to the state in which the elastic sheet 3 starts to deform. In an ideal state, the elastic sheet 3 does not deform in the initial state, but due to the allowable error in the process of part machining, the elastic sheet 3 will have a slight deformation, and the slight deformation has little effect on the service life of the elastic sheet 3. In general, the deformation of the elastic sheet 3 is the same state, i.e. the initial deformation state, when it is in the initial position each time.

[0098] As Figure 14 and Figure 15As shown, specifically, in one embodiment, the zero position platform 13 comprises a platform body 131 and a mounting platform 132, wherein the platform body 131 is provided with a cavity extending through from top to bottom along the direction in which the pull shaft body extends; the mounting platform 132 is protruded on the inner wall of the cavity near the first opening 11, and the mounting platform 132 is provided with a third mounting hole 133 with an opening facing the first opening 11, which is used for assembling the elastic sheet 3 on the mounting platform 132; when the elastic sheet 3 is in the same horizontal plane as the mounting platform 132, the elastic sheet 3 is always in the initial deformation state. Fixing the initial deformation position of the elastic sheet 3 makes the zero position of the load cell not drift, thereby improving the measurement accuracy of the load cell.

[0099] It should be understood that the shape and number of the mounting platform 132 are related to the structural design of the elastic sheet 3, and are not limited to the above embodiment, and can be specifically designed according to actual conditions.

[0100] In one embodiment, as shown in Figure 6 , Figure 7 The zero position platform 13 further comprises a cover 134 arranged in the cavity, the cover 134 is provided with an assembly groove for assembling the connecting end 22 along the direction in which the pull shaft body extends, and the height of the cover 134 is lower than the height of the mounting platform 132 in the direction in which the pull shaft body extends. In the case that the free end 21 of the pull shaft body is not subjected to external force, the connecting end 22 of the pull shaft 2 contacts the bottom surface away from the first opening 11 or the end surface near the first opening 11 of the cover 134, at this time, the elastic sheet 3 is in the initial deformation position, thereby forming the zero point of the load cell. This structural design facilitates the assembly of parts and saves production costs.

[0101] It can be understood that the elastic sheet 3 is assembled on the same side of the mounting platform 132 and the third limiting structure 23, i.e., the protrusion. In order to better improve the service life of the elastic sheet 3, in an optional embodiment, the elastic sheet 3 is assembled on the side away from the first opening 11, so as to avoid direct contact or indirect contact of the elastic sheet 3 with the load bearing member 4, thereby improving the service life of the elastic sheet 3.

[0102] Regarding the fixation of the cover 134 and the shell 1, in one embodiment, the outer surface of the cover 134 is circumferentially provided with a third thread, and the inner wall of the cavity of the platform body 131 is circumferentially provided with a fourth thread matched with the third thread. That is, the cover 134 is screwed into or out of the cavity of the platform body 131, which facilitates the installation and disassembly of the cover 134 and saves assembly and maintenance costs.

[0103] When the free end 21 of the pull shaft body is subjected to force, the connecting end 22 of the pull shaft 2 can be displaced along the extension direction of the pull shaft body, and at the same time, it can also cause the elastic sheet 3 to deform. At this time, it is necessary to design the connection of the connecting end 22 of the pull shaft 2. In one embodiment, the connecting end 22 is movably assembled in the assembly groove of the cover 134. A snap-fit ​​or sliding connection can be used. In this application, a snap-fit ​​method is preferred to reduce the production cost of the parts.

[0104] Regarding the specific structural design of the connecting end 22 of the pull shaft body, as follows: Figure 6 and Figure 7 As shown, in one embodiment, the pull shaft body further includes a top shaft 24 detachably assembled with the connecting end 22 of the pull shaft 2. The top shaft 24 is configured to be movably assembled within the cover 134, and when the top shaft 24 is stationary relative to the cover 134, the elastic sheet 3 is simultaneously in its initial deformation state. The detachable connection between the connecting end 22 and the top shaft 24 is designed to be detachable, and the top shaft 24 allows the connecting end 22 to reciprocate axially relative to the housing 1, facilitating the assembly of the entire weighing sensor and subsequent maintenance, reducing procedures, and saving costs.

[0105] Based on the specific mechanism design of the connecting end 22, in order to achieve contact between the connecting end 22 and one end of the cover 134, and to achieve the zero position, such as Figure 6 In one embodiment, the end of the assembly groove away from the first opening 11 has a bottom surface. When the end face of the top shaft away from the first opening 11 contacts the bottom surface, the elastic sheet 3 does not deform. In the above solution, the assembly method of the cover and the top shaft is simple to design and easy to implement.

[0106] Based on different capping 134 designs, such as Figure 7 In another embodiment shown, the assembly groove of the cover 134 is a through groove, and a limiting protrusion 25 is formed on the outer surface of the top shaft 24. When the surface of the limiting protrusion 25 away from the first opening 11 contacts the groove of the assembly groove near the first opening 11, the elastic sheet 3 does not deform. In the above scheme, the assembly method of the cover and the top shaft is simple to design and easy to implement.

[0107] It is understandable that, through the structural design of the cover 134 or the top shaft, when the main body of the pull shaft is not subjected to external force, the end face of the connecting end 22 of the pull shaft body away from the first opening 11 is limited, serving as the starting point for its displacement after being subjected to force. At this time, the elastic sheet 3 does not move, thus defining the zero point position of the weighing sensor.

[0108] Specifically, after the connecting end 22 of the pull shaft 2 passes through the elastic sheet 3, the connecting end body 221 is screwed into the top shaft, and the cover 134 is fixed by being screwed into the shell 1. At this time, according to the design requirements, the top shaft abuts against the bottom surface or the end surface of the cover 134, so that the elastic sheet 3 is in the same horizontal plane as the mounting platform 132. At this time, no displacement occurs in the axial direction of the pull shaft body, and the elastic sheet 3 is in the initial zero position. As the pull shaft 2 is pulled, the top shaft moves away from the bottom surface or the end surface of the cover 134, and drives the elastic sheet 3 to axially displace. When the external force for pulling the pull shaft 2 disappears, the pull shaft 2 is pressed against the bottom surface or the end surface of the cover 134 by the elastic force of the disc spring assembly, so that the elastic sheet 3 returns to the initial deformation position.

[0109] It should be understood that, based on the above principle, appropriate structures of the cover 134, the top shaft 24 and the connecting end 22 and / or the assembly scheme therebetween can be selected according to different design of the cover 134 and the design of the top shaft 24 and the connecting end 22, and are not limited to the above embodiments.

[0110] Since the load cell needs to be kept in displacement in the extension direction of the pull shaft body during operation, radial limiting needs to be performed between the pull shaft body and the top shaft. In an embodiment, the load cell further comprises a radial limiting structure arranged between the pull shaft 2 and the hollow cavity and used for limiting the movement of the pull shaft body relative to the shell 1 in the radial direction of the pull shaft body.

[0111] Different radial limiting structures are arranged according to different structures of the cover 134, such as shown in FIG. 6. Figure 6 In an embodiment, the assembly groove of the cover 134 is provided with a bottom surface away from one end of the first opening 11, and the radial limiting structure comprises a first sleeve 71 or a second sleeve 72. The first sleeve 71 is sleeved on the pull shaft body and close to the free end 21, and the second sleeve 72 is sleeved between the top shaft and the cover 134. Preferably, the first sleeve 71 and the second sleeve 72 are copper sleeves, which reduces the friction during the movement of the pull shaft 2 and improves the measurement accuracy of the load cell.

[0112] Specifically, the above embodiment includes three schemes: in the first scheme, the second sleeve 72 is arranged between the top shaft 24 of the load cell and the cover 134; in the second scheme, the first sleeve 71 is arranged between the pull shaft 2 of the load cell close to the first opening 11 and the shell 1; and in the third scheme, the first sleeve 71 is arranged between the pull shaft 2 of the load cell close to the first opening 11 and the shell 1, and the second sleeve 72 is arranged between the top shaft 23 of the load cell and the cover 134. The third scheme is preferred in terms of the stability of the radial limiting of the pull shaft 2. It should be understood that the number of sleeves and the positions of the sleeves can be selected according to actual conditions and product requirements, and are not limited to the above embodiments.

[0113] The movement of the pull shaft body after receiving external force is radially limited by the copper sleeves on the pull shaft body and the top shaft 24, ensuring that it can only move in the radial direction perpendicular to the pull shaft body, i.e., along the extension direction of the pull shaft body. This also ensures that the elastic plate 3 can only move in the extension direction of the pull shaft body. This avoids friction between the pull shaft body and the inner shell 1 during the movement of the pull shaft body, which not only improves the measurement accuracy but also extends the service life of the weighing sensor.

[0114] like Figure 7 In another embodiment shown, the mounting groove of the cover 134 is a through groove, and the radial limiting structure includes a mounting groove and a flexible rubber sheet 74. The mounting groove is located on the circumferential direction of the outer surface of the pull shaft body, and the plane where the mounting groove is located is perpendicular to the extension direction of the pull shaft body. The flexible rubber sheet 74 is fitted in the mounting groove and forms an interference fit with the inner wall of the hollow cavity.

[0115] Utilizing the specific material properties of the flexible rubber sheet 74, it provides excellent restraint on the pull shaft body in the radial direction perpendicular to its extension, without affecting its movement along the axial direction. Furthermore, unlike the copper sleeve, which requires the force on the free end 21 of the pull shaft body to be as perpendicular as possible when used as a restraining structure, this solution addresses the problem of increased friction between the radial restraining structure and the pull shaft body or housing 1, which affects the test results, due to the force direction on the free end 21 of the pull shaft body not being parallel to its extension direction.

[0116] Regarding the specific installation scheme of the flexible rubber sheet 74, in an optional embodiment, the mounting groove includes a first mounting groove 731 and a second mounting groove 732, wherein the first mounting groove 731 is located at the end of the top shaft away from the cover 134, and the second mounting groove 732 is located at the free end 21 and near the first opening 11; the flexible rubber sheet 74 includes a first rubber sheet and a second rubber sheet, wherein the first rubber sheet is installed in the first mounting groove 731 and contacts the end face of the cover 134 away from the first opening 11, and the second rubber sheet is installed in the second mounting groove 732 and located in the first opening 11.

[0117] Specifically, a flexible rubber sheet 74 is installed on the housing 1, with one flexible rubber sheet 74 on the top and one on the bottom of the housing 1. A first mounting groove 731 is provided on the top shaft 24, and a second mounting groove 732 is provided on the free end 21 of the pull shaft body, so that the flexible rubber sheet 74 can be installed into the mounting groove, which facilitates the installation and maintenance of the device.

[0118] In order to cooperate with the first limiting cavity to limit the displacement of the pull shaft body and protect the service life of the elastic sheet 3, such as Figure 6 , Figure 7As shown in one embodiment, a third limiting structure is provided on the pull shaft body near the connecting end 22. The third limiting structure is located in the first limiting cavity and can only reciprocate within the first limiting cavity, thereby limiting the magnitude of the movement displacement of the pull shaft body and improving the service life of the elastic sheet 3.

[0119] In one embodiment, the third limiting structure 23 is a circumferentially distributed boss on the outer wall of the pull shaft body. The boss has a notch 231, which is adapted to the shape of the mounting platform 131 on the inner wall of the hollow cavity for assembling the elastic sheet 3. When the notch 231 engages with the mounting platform 131, the elastic sheet 3 is in its initial deformed state. The cross-sectional area of ​​the boss is larger than the maximum cross-sectional area of ​​the second limiting cavity, and smaller than the minimum cross-sectional area of ​​the first limiting cavity. This structure limits the displacement of the reciprocating motion of the pull shaft body, and the boss on the pull shaft body facilitates manufacturing and saves production costs.

[0120] Specifically, when the pull shaft 2 of the load cell bears a heavy load exceeding the design requirements, the boss on the pull shaft 2 will be stuck at the interface between the first limiting cavity and the second limiting cavity, protecting the disc spring assembly from being compressed and thus preventing the elastic sheet 3 from being damaged due to excessive displacement.

[0121] like Figure 1 , Figure 2 In one embodiment, the connection line between the notch 231 of the boss and the boss is not a straight line. It is understood that this non-straight line can be a curve, a broken line, a wavy line, or other lines, which makes the notch 231 irregular in shape. After it is adapted to the mounting platform 131, it can prevent the pull shaft 2 from twisting relative to the mounting platform 131, i.e., the housing 1. Therefore, the pull shaft 2 has the ability to resist torsion, thereby solving the problem of the elastic sheet 3 being damaged after bearing torsional force.

[0122] To achieve a large range of weighing sensors, such as Figure 10The application also designs the elastic sheet 3. In one embodiment, the elastic sheet 3 comprises: a mounting arm 31 and an extension arm 33, the mounting arm 31 and the extension arm 33 are integrally formed into a sheet structure extending outward in a spiral shape from the mounting arm 31 to the extension arm 33, wherein one of the mounting arm 31 and the extension arm 33 is provided with a first mounting structure for mounting the elastic sheet 3 on the shell 1, and the other is provided with a second mounting structure for mounting the elastic sheet 3 on the connecting end 22, so that the mounting arm 31 elastically moves relative to the extension arm 33 when the connecting end 22 moves relative to the shell 1 in the elastic force direction of the elastic sheet 3. The elastic sheet 3 is made into a spiral shape, which is conducive to generating a more ideal strain field of the elastic sheet 3, and makes the deformation of the elastic sheet 3 more sensitive. In the case of a very small force, the elastic sheet 3 will deform, thereby improving the measurement accuracy of the load sensor.

[0123] In one embodiment, the extension arm 33 is provided with a first mounting structure for mounting the elastic sheet 3 on the shell 1, i.e. the mounting platform 131, and the mounting arm 31 is provided with a second mounting structure for mounting the elastic sheet 3 on the connecting end 22, and the mounting arm 31 moves as the starting end of the threaded shape with the connecting end 22 of the pull shaft 2, so that the mounting arm 31 deforms relative to the extension arm 33, generating a more ideal deformation field and improving the measurement accuracy of the load sensor. It should be understood that, according to the specific structure of the elastic sheet 3 or the structure of the shell 1, the extension arm 33 can also be made to move relative to the mounting arm 31, so that the elastic sheet 3 deforms. The actual situation can be designed accordingly.

[0124] In one embodiment, the second mounting structure is a fourth mounting hole 34, i.e. through the fourth mounting hole 34 on the mounting arm 31, the elastic sheet 3 is directly sleeved on the pull shaft 2, so that the mounting arm 31 of the elastic sheet 3 moves with the movement of the pull shaft 2, and then the elastic sheet 3 deforms. This scheme is simple in process, easy to assemble, improves production efficiency, and reduces production cost. It should be understood that the size of the fourth mounting hole 34 can be adjusted according to different product use requirements, thereby improving the applicability of the elastic sheet 3.

[0125] In one embodiment, the elastic sheet 3 further comprises a connecting arm 32 connecting the mounting arm 31 and the extension arm 33, and the rotation angle of one end of the connecting arm 32 to the other end of the connecting arm 32 is β, and 0°<β<360°. The stroke of the elastic sheet 3 is increased while the elastic deformation is protected, so that the surface stress is much smaller than the yield force, thereby increasing the service life.

[0126] As Figure 10In the embodiment shown, when β = 270°, the connecting arm 32 comprises a first vertical arm 321, a first horizontal arm 322 and a second vertical arm 323, wherein one end of the first vertical arm 321 is connected with the mounting arm 31; the first horizontal arm is parallel to the mounting arm 31 and one end of the first horizontal arm is connected with the other end of the first vertical arm 321; the second vertical arm 323 is parallel to the first vertical arm 321 and one end of the second vertical arm 323 is connected with the other end of the first horizontal arm, and the other end of the second vertical arm 323 is connected with one end of the extension arm 33.

[0127] As shown in the embodiment, when β = 180°, the connecting arm 32 comprises a third vertical arm 324 and a second horizontal arm 325, wherein one end of the third vertical arm 324 is connected with the mounting arm 31; the second horizontal arm 325 is parallel to the mounting arm 31 and one end of the second horizontal arm 325 is connected with the other end of the third vertical arm 324, and the other end of the second horizontal arm 325 is connected with the extension arm 33. Figure 11 As shown in the embodiment, when β = 90°, the connecting arm 32 comprises a third horizontal arm 326, and both ends of the third horizontal arm 326 are connected with the mounting arm 31 and the extension arm 33 respectively.

[0128] Figure 12 As shown in the embodiment, when β = 90°, the connecting arm 32 comprises a third horizontal arm 326, and both ends of the third horizontal arm 326 are connected with the mounting arm 31 and the extension arm 33 respectively.

[0129] As shown in the embodiment, when β = 90°, the connecting arm 32 comprises a third horizontal arm 326, and both ends of the third horizontal arm 326 are connected with the mounting arm 31 and the extension arm 33 respectively. Figure 11 In the embodiment shown, at least one first assembly hole 331 is arranged on the extension arm 33, and a fastener passes through the first assembly hole 331 and a second assembly hole 133 arranged on the housing 1 to assemble the elastic sheet 3 to the housing 1, specifically to the zero platform 13 of the housing 1.

[0130] In the embodiment shown, at least one first assembly hole 331 is arranged on the extension arm 33, and a fastener passes through the first assembly hole 331 and a second assembly hole 133 arranged on the housing 1 to assemble the elastic sheet 3 to the housing 1, specifically to the zero platform 13 of the housing 1.

[0131] In the embodiment shown, at least one first assembly hole 331 is arranged on the extension arm 33, and a fastener passes through the first assembly hole 331 and a second assembly hole 133 arranged on the housing 1 to assemble the elastic sheet 3 to the housing 1, specifically to the zero platform 13 of the housing 1.

[0132] Figure 2 In the embodiment shown, at least one first assembly hole 331 is arranged on the extension arm 33, and a fastener passes through the first assembly hole 331 and a second assembly hole 133 arranged on the housing 1 to assemble the elastic sheet 3 to the housing 1, specifically to the zero platform 13 of the housing 1. Figure 13 In the embodiment shown, at least one first assembly hole 331 is arranged on the extension arm 33, and a fastener passes through the first assembly hole 331 and a second assembly hole 133 arranged on the housing 1 to assemble the elastic sheet 3 to the housing 1, specifically to the zero platform 13 of the housing 1.

[0133] ​​Specifically, after the extension arm 33 of the elastic sheet 3 is positioned on the mounting platform 132 of the shell 1, the gasket 8 is arranged on the assembly surface of the extension arm 33, and then the fastener passes through the gasket 8, the elastic sheet 3, and the mounting platform 132 in sequence, so as to finally realize the fixation of the elastic sheet 3 and the shell 1. The gasket 8 is in direct contact with the force receiving end of the fastener, and after the fastener locks the elastic sheet, the gasket 8 avoids the slight deformation of the elastic sheet 3 caused by the torsion on the surface of the elastic sheet 3, improves the precision of the elastic sheet 3, and further improves the precision of the load sensor.

[0134] In an embodiment, the elastic sheet 3 is made of 65Mn spring steel sheet, and the thickness is 0.3mm-0.5mm. From the comprehensive performance, i.e., the production cost, the processing technology, and the performance of the elastic sheet 3, the design of the thickness of the elastic sheet 3 can meet the requirements.

[0135] It can be understood that the designer can also reset the thickness of the elastic sheet 3 according to the scene in which the elastic sheet 3 is used. The material used to prepare the elastic sheet 3 is the existing material, which saves the production cost. It can be understood that when there are other functional requirements for the elastic sheet 3, the material used to prepare the elastic sheet 3 can also be improved. For example, when the elastic sheet 3 needs to have magnetism, the material used to prepare the elastic sheet 3 can be a material with magnetism. Specifically, the elastic sheet 3 can be a steel sheet with magnetism by doping the existing material or other processing technologies.

[0136] In an embodiment, the load sensor further comprises a strain sheet arranged on the elastic sheet 3, which converts the strain change of the elastic sheet into an electrical signal and outputs, so as to realize the load measurement.

[0137] In summary, the load sensor comprises a shell, a pull shaft, an elastic sheet, and a load bearing. The shell comprises a hollow cavity with a first opening at the top. The pull shaft comprises a pull shaft body, one end of which is a free end, and the other end of which is a connecting end. The connecting end is arranged in the hollow cavity, and the free end is used to connect a load to be measured. The pull shaft body can make axial reciprocating motion relative to the hollow cavity. The elastic sheet is arranged in the hollow cavity and synchronously moves with the reciprocating motion of the pull shaft body and generates deformation. The load bearing is arranged in the hollow cavity and located between the free end and the connecting end. Under the effective force of the external force applied to the free end, the load bearing is compressed under stress, and the pull shaft body moves and drives the elastic sheet to move and generate deformation. The effective force is the component of the external force in the direction parallel to the extension direction of the pull shaft body. The load bearing is used as the main component to bear the external force, which avoids the direct stress on the elastic sheet and prolongs the service life of the elastic sheet.

[0138] In the description of the application, reference to "one embodiment", "some embodiments", "an example", etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. The appearances of the phrases "in one embodiment", "in some embodiments", "an example", etc., in various places in the specification are not necessarily all referring to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0139] 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 application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0140] In addition, the terms "first", "second", etc., are used herein only to describe various conditions, and are not to be construed as indicating or implying relative importance or a specific number of features indicated thereby, such that the features defined with "first", "second", etc., can include at least one of the features explicitly or implicitly.

[0141] The above description is merely illustrative of the application, and is not to be taken in a limiting sense. Any modification and / or equivalent arrangement of the application, which was made within the spirit and principles of the application, is intended to be included in the scope of the application.

Claims

1. A weighing sensor, characterized in that, include: The housing includes a hollow cavity with a first opening; A pull shaft includes a pull shaft body, one end of which is a free end and the other end of which is a connecting end, wherein the connecting end is disposed in the hollow cavity and the pull shaft body can move axially relative to the hollow cavity; An elastic sheet is disposed within the hollow cavity and can deform as the main body of the pull shaft moves. A load-bearing component is disposed within the hollow cavity and located between the free end and the connecting end. Under the effective force of an external force applied to the free end, the load-bearing component is compressed, while the main body of the pull shaft moves and drives the elastic sheet to move, thus generating deformation. The effective force is the component of the external force in the direction parallel to the extension direction of the main body of the pull shaft. The hollow cavity contains a first limiting cavity and a second limiting cavity that are connected in sequence in the direction toward the first opening. The second limiting cavity is disposed between the first limiting cavity and the first opening and is used to limit the load-bearing member between the first opening and the elastic sheet. The weighing sensor further includes a load adjusting component, which is disposed at the first opening and sleeved on the outer periphery of the pull shaft body, and is used to adjust the magnitude of the preload applied to the load bearing component. The weighing sensor further includes a locking device, wherein a mounting cavity is formed in the hollow cavity between the second limiting cavity and the first opening, the load adjusting member extends into the second limiting cavity through the mounting cavity, and the locking device is disposed outside the mounting cavity to reinforce the connection between the load adjusting member and the housing by tightening the mounting cavity.

2. The weighing sensor as described in claim 1, characterized in that, The first limiting cavity is relatively far from the first opening, and the minimum cross-sectional area of ​​the first limiting cavity is greater than the maximum cross-sectional area of ​​the second limiting cavity, which is used to limit the displacement of the reciprocating motion of the pull shaft body.

3. The weighing sensor as described in claim 1, characterized in that: The load-bearing component is a disc spring assembly, which includes multiple disc spring unit groups, wherein each disc spring unit group includes: The first single disc spring has a cross-sectional structure of a first conical structure, and the top of the first conical structure is provided with a first mounting hole; The second single disc spring has a cross-sectional structure that is a second conical structure, and the top of the second conical structure is provided with a second mounting hole; The first single-piece disc spring is located below the second single-piece disc spring, and the top of the first conical structure is aligned with the top of the second conical structure; the first single-piece disc spring and the second single-piece disc spring are coaxially sleeved on the pull shaft body through the first mounting hole and the second mounting hole, respectively.

4. The weighing sensor as described in claim 2, characterized in that, The end of the load-bearing member away from the first opening is fixed relative to the pull shaft, and the end of the load-bearing member close to the first opening is in contact with the first end face of the load adjusting member away from the first opening.

5. The weighing sensor as described in claim 4, characterized in that, The load adjusting member extends into the second limiting cavity, and a limiting structure is provided on the first end face to limit the end of the load bearing member facing the first opening on the load adjusting member.

6. The weighing sensor as described in claim 5, characterized in that, The hollow cavity also contains a mounting cavity located between the second limiting cavity and the first opening. The load adjusting member extends through the mounting cavity into the second limiting cavity. The inner wall of the mounting cavity is provided with a first displacement adjustment structure, and the outer wall of the load adjustment member is correspondingly provided with a second displacement adjustment structure. The first displacement adjustment structure and the second displacement adjustment structure cooperate to fix the load adjustment member in the mounting cavity and adjust the length of the load adjustment member extending into the second limiting cavity.

7. The weighing sensor as described in claim 1, characterized in that, The inner wall of the mounting cavity is parallel to the inner wall of the second limiting cavity, and the outer wall of the mounting cavity forms an angle γ with the outer wall of the second limiting cavity, where 0° < γ < 90°.

8. The weighing sensor as described in claim 7, characterized in that, The locking device includes: The locking body is a cavity, including a connecting part for connecting to the outer wall of the second limiting cavity and a pressing part for pressing the outer wall of the mounting cavity, wherein the inner wall of the connecting part and the inner wall of the pressing part form an angle δ, and δ≥γ; The third displacement adjustment structure is disposed on the inner wall of the connecting part and cooperates with the fourth displacement adjustment structure disposed on the outer wall of the mounting cavity to adjust the displacement of the connecting part relative to the second limiting cavity.

9. The weighing sensor as described in claim 1, characterized in that, In the direction of extension of the pull shaft body, a fine groove is formed, starting from the position of the second limiting cavity near the mounting cavity, extending through the mounting cavity to the first opening.

10. The weighing sensor as described in claim 1, characterized in that, The locking device includes a locking bolt, which works in conjunction with a through hole on the load adjusting member and a threaded hole on the housing that communicates with the through hole.

11. The weighing sensor as described in claim 1, characterized in that, It also includes a zero-position platform, the connecting end is disposed on the zero-position platform and can reciprocate relative to the zero-position platform in the direction of the zero-position platform toward the first opening; the elastic sheet is disposed on the connecting end and deforms with the reciprocating motion, and the elastic sheet is in the initial deformation state when the connecting end is stationary on the zero-position platform.

12. The weighing sensor as described in claim 11, characterized in that, The zero-position platform includes: The platform body has a cavity that extends vertically along the direction of the pull shaft body; An installation platform is protruding from the inner wall of the hollow cavity. The installation platform is provided with a third installation hole with an opening facing the first opening. The third installation hole is used to assemble the elastic sheet on the installation platform. When the elastic sheet and the installation platform are on the same horizontal plane, the elastic sheet is always in the initial deformation state.

13. The weighing sensor as described in claim 12, characterized in that, The zero-position platform further includes a cover disposed within the cavity, the cover having an assembly groove for assembling the connecting end along the extension direction of the pull shaft body, and the height of the cover being lower than the height of the mounting platform in the extension direction of the pull shaft body.

14. The weighing sensor as described in claim 13, characterized in that, The pull shaft body also includes a top shaft that is detachably assembled with the connecting end. The top shaft is configured to be movably assembled inside the cover, and when the top shaft is stationary relative to the cover, the elastic sheet is simultaneously in the initial deformation state.

15. The weighing sensor as described in claim 14, characterized in that, It also includes a radial limiting structure, which is disposed between the pull shaft and the hollow cavity to limit the movement of the pull shaft body relative to the housing in the radial direction of the pull shaft body.

16. The weighing sensor as described in claim 15, characterized in that, The end of the mounting groove of the cap away from the first opening has a bottom surface, and the radial limiting structure includes a first sleeve and / or a second sleeve, wherein... The first sleeve is fitted onto the pull shaft body and is close to the free end; The second sleeve is fitted between the top shaft and the cover.

17. The weighing sensor as described in claim 2, characterized in that, A third limiting structure is provided on the main body of the pull shaft near the connecting end. The third limiting structure is located in the first limiting cavity and can only reciprocate within the first limiting cavity.

18. The weighing sensor as described in claim 17, characterized in that, The third limiting structure is a boss distributed circumferentially on the outer wall of the pull shaft body. The boss has a notch, which is adapted to the shape of the mounting platform protruding on the inner wall of the hollow cavity for assembling the elastic sheet. When the notch mates with the mounting platform, the elastic sheet is in the initial deformation state.

19. The weighing sensor as described in claim 18, characterized in that, The connection line between the notch of the mounting platform and the boss is not a straight line.

20. The weighing sensor as described in claim 1, characterized in that, The elastic sheet includes a mounting arm and an extension arm, and the elastic sheet is an integrally formed sheet structure extending outward in a spiral shape from the mounting arm to the extension arm. One of the mounting arm and the extension arm is provided with a first mounting structure for assembling the elastic sheet onto the housing, and the other is provided with a second mounting structure for mounting the elastic sheet onto the connecting end, so that when the connecting end moves relative to the housing in the elastic direction of the elastic sheet, the mounting arm moves elastically relative to the extension arm.

21. The weighing sensor as described in claim 20, characterized in that, The elastic sheet also includes a connecting arm that connects the mounting arm and the extension arm, and the rotation angle from one end of the connecting arm to the other end of the connecting arm is β, where 0° < β < 360°.

22. The weighing sensor as described in claim 20, characterized in that, The extension arm is provided with at least one first mounting hole, and the fastener passes through the first mounting hole and the second mounting hole provided on the housing to assemble the elastic sheet onto the housing.

23. The weighing sensor as described in claim 22, characterized in that, It also includes a gasket disposed on the end face of the extension arm toward the force-applying end of the fastener.

24. The weighing sensor as described in claim 20, characterized in that, The extension arm is also provided with at least one positioning hole, which cooperates with the positioning post provided on the housing to limit the elastic sheet on the housing.

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