Weighing device

Abstract

The invention discloses a weighing device which comprises a bearing plate, at least three weighing units are distributed on the lower side of the bearing plate at intervals in a non-linear mode, the weighing units stably support the bearing plate, the middle of the bearing plate is bent and sunken downwards to form a loading area used for bearing external heavy objects, and force transmission areas used for being connected with the weighing units are formed on the edge portions of the bearing plate. Under the maximum load, the bottom surface of the loading area is not lower than the grounding point of the weighing unit. The suspension height of the external weight is equal to the ground clearance of the upper surface of the loading area, and the loading area is formed by bending and sinking the middle of the bearing plate downwards, so that the upper surface of the loading area is inevitably lower than the upper surface of the force transmission area, namely, the ground clearance of the loading area is inevitably smaller than the sum of the thickness of the force transmission area and the thickness of the weighing unit. Therefore, when the weighing device in the embodiment is used for weighing the external heavy object, the ground clearance of the external heavy object can be correspondingly reduced, so that the application range can be widened, and the stability of the external heavy object in the weighing process can be enhanced.

Description

Technical Field

[0001] The invention mainly relates to the technical field of gravity measuring devices, and in particular to a weighing device. Background Art

[0002] A weighing device is a device equipped with a weighing sensor (weighing unit) for converting mass signals into measurable electrical signal outputs. Weighing sensors are divided into eight categories according to the conversion method: photoelectric, hydraulic, electromagnetic, capacitive, magnetic pole change, vibration, gyroscopic and resistance strain, among which the resistance strain is the most widely used. The resistance strain weighing sensor is mainly composed of four parts: elastic element, resistance strain gauge, measurement circuit and transmission cable. Its working principle is that the elastic body produces elastic deformation under the action of external force, so that the resistance strain gauge attached to its surface also produces deformation. After the resistance strain gauge is deformed, its resistance value will change, and then the corresponding measurement circuit will convert this resistance change into an electrical signal, thereby completing the process of converting external force into an electrical signal.

[0003] The weighing device in the prior art is provided with a load-bearing plate, and a number of weighing units are arranged at intervals at the edge of the load-bearing plate. When a heavy object is placed on the load-bearing plate, the elastic element and the resistance strain gauge in the weighing unit are deformed so that gravity information can be obtained through the measuring circuit. The load-bearing plates in the prior art are all flat plate structures, and the weighing units are arranged on the lower side of the load-bearing plate, so the suspended height of the external heavy object is equal to the sum of the thickness of the load-bearing plate and the weighing unit. In some specific usage scenarios, the suspended height (center of gravity height) of the heavy object should not be too large (for example, the weighing device set under the foot or bed wheel of a gravity-type sleep monitoring bed, if the foot or bed wheel suspended height is too large, the bed body will be due to the upward shift of the center of gravity, resulting in reduced stability, and it is difficult to complete the installation), so the weighing device in the prior art is difficult to meet the requirements. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a weighing device.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A weighing device comprises a load-bearing plate, at least three weighing units are distributed at non-linear intervals on the lower side of the load-bearing plate, the weighing units stably support the load-bearing plate, the middle part of the load-bearing plate is bent downward and recessed to form a loading area for carrying external heavy objects, and its edge part forms a force transmission area for connecting the weighing units. Under the maximum load, the bottom surface of the loading area is not lower than the contact point of the weighing units.

[0007] As a further improvement of the above technical solution:

[0008] The loading area is configured as a flat plate.

[0009] The weighing unit includes an elastic plate extending outward along the edge of the force transmission area, a resistance strain gauge spanning the elastic plate and the force transmission area and attached to the lower surfaces of the two, and a support member arranged under the elastic plate. Under the maximum load, the contact point of the support member is not higher than the bottom surface of the loading area.

[0010] The elastic plate and the bearing plate are formed by stamping the same elastic plate.

[0011] The elastic plate includes a middle beam connected to the force transmission area, and side beams connected to the middle beam and symmetrically distributed on both sides thereof. The support member is arranged in an arch shape, spanning the middle beam and forming a connection with the two side beams.

[0012] The resistance strain gauge is coated with flexible sealant.

[0013] The resistance strain gauge is connected to the controller interface via a wire.

[0014] The resistance strain gauges are connected via wires to form a full-bridge circuit structure.

[0015] Compared with the prior art, the advantages of the present invention are:

[0016] In the prior art, the suspended height of the external weight is equal to the sum of the thicknesses of the flat-plate bearing plate and the weighing unit (equivalent to the sum of the thicknesses of the force transmission area and the weighing unit), while in the present application, the suspended height of the external weight is equal to the height of the upper surface of the loading area from the ground, because the loading area is formed by the middle part of the bearing plate being bent downward and concave, so that the upper surface of the loading area must be lower than the upper surface of the force transmission area, that is, the height of the loading area from the ground must be less than the sum of the thicknesses of the force transmission area and the weighing unit. Therefore, when the weighing device in this embodiment is used to weigh the external weight, the height of the external weight from the ground can be reduced accordingly, thereby widening the scope of application and enhancing the stability of the external weight during the weighing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the structure of the weighing device. Figure 1 ;

[0018] Figure 2 This is a schematic diagram of the structure of the weighing device. Figure 2 .

[0019] The numbers in the figure represent: 1. load-bearing plate; 11. loading area; 12. force transmission area; 2. weighing unit; 21. elastic plate; 211. middle beam; 212. side beam; 22. resistance strain gauge; 23. support; 24. wire; 25. controller interface. DETAILED DESCRIPTION

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] like Figure 1 and Figure 2 As shown, the weighing device of this embodiment includes a load-bearing plate 1, and four weighing units 2 are distributed nonlinearly at intervals on the lower side of the load-bearing plate 1 (in other embodiments, the number of weighing units 2 can also be set to three, five or more), and the four weighing units 2 stably support the load-bearing plate 1. The middle part of the load-bearing plate 1 is bent downward and recessed to form a load-bearing area 11 for carrying external heavy objects, and its edge portion forms a force transmission area 12 for connecting the weighing units 2. Under the maximum load, the bottom surface of the load-bearing area 11 is not lower than the contact point of the weighing units 2. Specifically, the load-bearing plate 1 is a square plate, and the four weighing units 2 are distributed on the four corners of the load-bearing plate 1. The bottoms of the four weighing units 2 touch the ground at the same time, thereby forming a stable support for the load-bearing plate 1. The middle part of the load-bearing plate 1 is bent downward and recessed to form a rectangular plane plate-shaped load-bearing area 11, which is used to carry external objects to be weighed. The two unrecessed edges of the load-bearing plate 1 form a force transmission area 12, and two weighing units 2 are connected to each of the two force transmission areas 12. When an external weight is placed on the loading area 11 of the loading plate 1, due to the action of gravity, the external weight applies a downward pressure to the loading plate 1, and the pressure is transmitted to the weighing unit 2 by the force transmission area 12, thereby completing the weighing operation. At the same time, due to the action of pressure, the bottom surface of the loading area 11 will move downward. Under the maximum load, the bottom surface of the loading area 11 is not lower than the ground contact point of the weighing unit 2, thereby preventing the loading area 11 from touching the ground and affecting the weighing result. In the prior art, the suspended height of the external weight is equal to the sum of the thickness of the flat loading plate 1 and the weighing unit 2 (equivalent to the sum of the thickness of the force transmission area 12 and the weighing unit 2), while in this embodiment, the suspended height of the external weight is equal to the height of the upper surface of the loading area 11 from the ground, because the loading area 11 is formed by the middle part of the loading plate 1 being bent downward and concave, so that the upper surface of the loading area 11 must be lower than the upper surface of the force transmission area 12, that is, the height of the loading area 11 from the ground must be less than the sum of the thickness of the force transmission area 12 and the weighing unit 2. Therefore, when using the weighing device in this embodiment to weigh external weights, the height of the external weights from the ground (center of gravity height) can be correspondingly reduced, thereby broadening the scope of application and enhancing the stability of the external weights during the weighing process.

[0022] In this embodiment, the weighing unit 2 includes an elastic plate 21 extending outward along the edge of the force transmission area 12, a resistance strain gauge 22 spanning the elastic plate 21 and the force transmission area 12 and attached to the lower surfaces of the two, and a support member 23 disposed below the elastic plate 21. Under the maximum load, the contact point of the support member 23 is not higher than the bottom surface of the object loading area 11. The support member 23 contacts the ground through a fixing device, and under the support of the support member 23, the load-bearing plate 1 and the elastic plate 21 are in a suspended state. When an external heavy object is placed on the object loading area 11, the intersection of the elastic plate 21 and the force transmission area 12 bends upward, and since the resistance strain gauge 22 spans the elastic plate 21 and the force transmission area 12 and is attached to the lower surfaces of the two, the resistance strain gauge 22 will also bend, thereby causing the resistivity to change. Furthermore, the elastic plate 21 and the bearing plate 1 are stamped from the same elastic plate, which means that each resistance strain gauge 22 is connected to the same steel plate. The performance of the same steel plate is highly consistent. Under the action of the same external force, the degree of bending between each elastic plate 21 and the force transmission area 12 is almost the same, thereby improving the measurement accuracy.

[0023] In this embodiment, the elastic plate 21 includes a middle beam 211 connected to the force transmission area 12, and side beams 212 connected to the middle beam 211 and symmetrically distributed on both sides thereof, and the support member 23 is arranged in an arch shape, which spans the middle beam 211 and forms a connection with the two side beams 212. The middle beam 211 is connected to the force transmission area 12 to ensure the accuracy of force transmission, and the side beams 212 connected to the middle beam 211 and symmetrically distributed on both sides thereof are arranged to enhance the stability of the elastic plate 21 and the accuracy of force transmission on the one hand, and provide an installation foundation for the support member 23 on the other hand, thereby improving the stability of the overall device.

[0024] In this embodiment, the resistance strain gauge 22 is coated with a flexible sealant, which not only ensures the accuracy of force transmission but also provides protection for the resistance strain gauge 22 and prevents it from being contaminated by the outside world, thereby increasing the service life of the device.

[0025] In this embodiment, the resistance strain gauge 22 is connected to the controller interface 25 via the wire 24. The resistance strain gauge 22 bends when subjected to force, thereby converting the sensed force into an electrical signal and transmitting it to the controller interface 25 through the wire 24. The external controller is connected to the controller interface 25 to read the electrical signal of the resistance strain gauge 22 and output it as the information required by the weighing device.

[0026] In this embodiment, the resistance strain gauges 22 are connected via wires 24 to form a full-bridge circuit structure, thereby reducing the number of wires required to connect the resistance strain gauges 22 and the external control device, improving reliability and stability, and facilitating assembly.

[0027] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any technician familiar with the art can make many possible changes and modifications to the technical solution of the present invention by using the technical content disclosed above without departing from the scope of the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention should fall within the scope of protection of the technical solution of the present invention.

Claims

1. A weighing device, comprising a load-bearing plate (1), at least three weighing units (2) being distributed non-linearly at intervals on the lower side of the load-bearing plate (1), wherein the weighing units (2) stably support the load-bearing plate (1), characterized in that: The middle portion of the load-bearing plate (1) is bent downward to form a load-bearing area (11) for bearing external heavy objects, and its edge portion forms a force transmission area (12) for connecting to a weighing unit (2). Under maximum load, the bottom surface of the load-bearing area (11) is not lower than the contact point of the weighing unit (2).

2. The weighing device according to claim 1, characterized in that: The loading area (11) is configured as a flat plate.

3. The weighing device according to claim 1, characterized in that: The weighing unit (2) comprises an elastic plate (21) extending outwardly along the edge of the force transmission area (12), a resistance strain gauge (22) spanning the elastic plate (21) and the force transmission area (12) and attached to the lower surfaces of the two, and a support member (23) arranged below the elastic plate (21), wherein under maximum load, the contact point of the support member (23) is not higher than the bottom surface of the load area (11).

4. The weighing device according to claim 3, characterized in that: The elastic plate (21) and the bearing plate (1) are formed by stamping the same elastic plate.

5. The weighing device according to claim 3, characterized in that: The elastic plate (21) comprises a middle beam (211) connected to the force transmission area (12), and side beams (212) connected to the middle beam (211) and symmetrically distributed on both sides thereof, and the support member (23) is arranged in an arch shape, spanning the middle beam (211) and forming a connection with the two side beams (212).

6. The weighing device according to claim 3, characterized in that: The resistance strain gauge (22) is coated with flexible sealant.

7. The weighing device according to claim 3, characterized in that: The resistance strain gauge (22) is connected to the controller interface (25) via a wire (24).

8. The weighing device according to claim 7, characterized in that: The resistance strain gauges (22) are connected via wires (24) to form a full-bridge circuit structure.

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