Weighing device
By using a hydraulic cylinder combination structure and lever principle, the number of weighing sensors is reduced, costs are lowered, and load-bearing capacity is increased, solving the problems of high cost and limited capacity of existing weighing devices and achieving high-precision weighing.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- METTLER TOLEDO (CHANGZHOU) MEASUREMENT TECH CO LTD
- Filing Date
- 2025-09-03
- Publication Date
- 2026-08-04
AI Technical Summary
Existing weighing devices require a large number of weighing sensors, resulting in high manufacturing costs and limited maximum load capacity, making it difficult to effectively improve the load capacity by increasing the number of sensors.
The system employs a combination of a first hydraulic cylinder and a second hydraulic cylinder. By leveraging the principle, the number of weighing sensors is reduced. The hydraulic cylinder transmits the downward pressure of the object, and the system, combined with hydraulic pipe assemblies, achieves accurate weighing.
It reduces the manufacturing cost of the weighing device, expands the maximum load capacity, improves weighing accuracy and flexibility, and reduces the dependence on the number of sensors.
Smart Images
Figure CN224594058U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of weighing technology, and specifically relates to a weighing device. Background Technology
[0002] To measure the weight of goods, existing weighing devices generally employ a multi-sensor support system. Specifically, multiple load cells are typically installed under the weighing platform. The combined action of these load cells forms a stable support surface, thus providing solid support for the weighing platform.
[0003] However, existing weighing devices have significant drawbacks in practical applications: On the one hand, weighing devices require a high number of load cells, and as precision measuring instruments, load cells are relatively expensive to produce. A larger number of load cells increases the manufacturing cost of the weighing device. On the other hand, the maximum load capacity of the weighing device is limited by both the number of load cells and the maximum load capacity of a single load cell. With a fixed maximum load capacity for a single load cell, increasing the maximum load capacity of the weighing device can only be achieved by increasing the number of load cells, further increasing the manufacturing cost and structural complexity of the weighing device.
[0004] The information disclosed in this background section is intended only to enhance the understanding of the overall background of this utility model and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Utility Model Content
[0005] The purpose of this invention is to provide a weighing device that solves the problem that existing weighing devices require a large number of weighing sensors.
[0006] To achieve the above objectives, a specific embodiment of this utility model provides a weighing device, which includes a weighing platform, a weighing sensor, a first hydraulic cylinder, and a second hydraulic cylinder. The weighing platform supports the object to be weighed, and the weighing sensor is located below the weighing platform, including a pressure-bearing portion arranged generally in a horizontal direction. The first hydraulic cylinder includes a first cylinder body, a first piston, and a first piston rod, with the first piston rod supporting the weighing platform from its bottom. The second hydraulic cylinder includes a second cylinder body, a second piston, and a second piston rod, with the second cylinder body communicating with the first cylinder body and having equal internal oil pressure. The pressure-bearing portion is positioned opposite the second piston rod to detect the force exerted when the second piston rod rests against it.
[0007] In one or more embodiments of this utility model, the first hydraulic cylinder and the second hydraulic cylinder are configured to satisfy: N×△A1>M×△A2. Wherein, N is the number of first hydraulic cylinders, △A1 is the difference in effective working areas on both sides of the first piston, M is the number of second hydraulic cylinders, and △A2 is the difference in effective working areas on both sides of the second piston.
[0008] In one or more embodiments of this utility model, the first piston rod includes a first main body portion extending through the end of the first cylinder body, and the second piston rod includes a second main body portion extending through the end of the second cylinder body. The first hydraulic cylinder and the second hydraulic cylinder are configured to satisfy: △A1=S1, △A2=S2. Wherein, S1 is the cross-sectional area of the first main body portion, and S2 is the cross-sectional area of the second main body portion.
[0009] In one or more embodiments of this utility model, the first main body and the second main body are cylindrical rod structures, and the first hydraulic cylinder and the second hydraulic cylinder are configured to satisfy: N×(D1) 2 >M×(D2) 2 Where D1 is the diameter of the first main body and D2 is the diameter of the second main body.
[0010] In one or more embodiments of this utility model, the first hydraulic cylinder and the second hydraulic cylinder are configured to satisfy: D1>D2, N≥2, M=1.
[0011] In one or more embodiments of this utility model, a first oil passage hole is provided on the first piston, and a second oil passage hole is provided on the second piston.
[0012] In one or more embodiments of this utility model, the weighing device further includes a hydraulic pipe assembly connected to the first cylinder and the second cylinder. The hydraulic pipe assembly includes multiple pipes, and two connected pipes are connected by a hydraulic joint.
[0013] In one or more embodiments of this utility model, at least two first hydraulic cylinders are provided, and the hydraulic pipe assembly is connected to all of the first cylinder bodies.
[0014] In one or more embodiments of this utility model, the second hydraulic cylinder extends horizontally and is positioned opposite the weighing sensor in the horizontal direction.
[0015] In one or more embodiments of this utility model, the pressure-bearing part is configured as a hole-like structure, and the end of the second piston rod near the pressure-bearing part is provided with a pressure-bearing member inserted into the pressure-bearing part.
[0016] Compared with the prior art, this utility model supports the weighing platform with a first hydraulic cylinder and uses the first and second hydraulic cylinders to transmit the downward pressure exerted by the object to be weighed on the weighing platform, which can reduce the number of weighing sensors and reduce the manufacturing cost of the weighing device. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 This is an exploded structural diagram of a weighing device according to an embodiment of the present invention;
[0019] Figure 2 This is another exploded structural diagram of the weighing device in one embodiment of the present invention;
[0020] Figure 3 This is a side view of the weighing device in one embodiment of the present invention;
[0021] Figure 4 This is a cross-sectional view of the first hydraulic cylinder in an unloaded state according to an embodiment of the present invention;
[0022] Figure 5 This is a cross-sectional view of the first hydraulic cylinder under load in one embodiment of the present invention;
[0023] Figure 6 This is a cross-sectional view of the second hydraulic cylinder in one embodiment of the present invention.
[0024] Key reference numerals in the attached drawings: 1. Weighing platform; 2. Weighing sensor; 21. Pressure bearing part; 3. First hydraulic cylinder; 31. First cylinder body; 311. First rodless chamber; 312. First rod chamber; 32. First piston; 321. First oil passage; 33. First piston rod; 331. First main body; 4. Second hydraulic cylinder; 41. Second cylinder body; 411. Second rodless chamber; 412. Second rod chamber; 42. Second piston; 421. Second oil passage; 43. Second piston rod; 431. Second main body; 5. Hydraulic pipe assembly; 51. Pipe; 52. Hydraulic joint; 53. First interface; 54. Second interface; 6. Bottom frame; 61. First support; 62. Second support; 63. Pivot shaft; 7. First connecting seat; 8. Second connecting seat; 9. Pressure bearing component. Detailed Implementation
[0025] To enable those skilled in the art to better understand the technical solutions in this disclosure, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this disclosure.
[0026] In the description of this utility model, it should be understood that the terms "top", "bottom", "upper", "lower", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0027] Furthermore, the terms "second" and "first" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined as "second" or "first" may explicitly or implicitly include one or more of the stated features. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.
[0028] Reference Figure 1 and Figure 3 As shown, one embodiment of the present invention provides a weighing device, which includes a weighing platform 1, a weighing sensor 2, a first hydraulic cylinder 3, a second hydraulic cylinder 4, a hydraulic pipe assembly 5, and a bottom frame 6.
[0029] Specifically, the weighing platform 1 is used to support the object to be weighed. The weighing platform 1 is located at the top of the bottom frame 6 and the two are connected by the first hydraulic cylinder 3. The weighing sensor 2 and the second hydraulic cylinder 4 are located below the weighing platform 1. The two do not contact the weighing platform 1 and are not used to support the weighing platform 1.
[0030] The first hydraulic cylinder 3 includes a first cylinder body 31, a first piston 32, and a first piston rod 33. The first cylinder body 31 is filled with hydraulic oil. The first piston 32 is located inside the first cylinder body 31. The bottom end of the first piston rod 33 is connected to the first piston 32, and the top end of the first piston rod 33 extends towards the bottom of the weighing platform 1, supporting the weighing platform 1 from the bottom of the weighing platform 1. The second hydraulic cylinder 4 includes a second cylinder body 41, a second piston 42, and a second piston rod 43. The second cylinder body 41 is also filled with hydraulic oil and is interconnected with the first cylinder body 31 through a hydraulic pipe assembly 5. The second piston 42 is located inside the second cylinder body 41. One end of the second piston rod 43 is connected to the second piston 42, and the other end of the second piston rod 43 extends outside the second cylinder body 41 and is positioned opposite to the pressure-bearing part 21 of the weighing sensor 2. When the second piston rod 43 and the pressure-bearing part 21 abut against each other, the second piston rod 43 applies a force to the pressure-bearing part 21, and the magnitude of the force can be obtained by the weighing sensor 2.
[0031] Furthermore, the first cylinder 31 has a first rodless chamber 311 and a first rod chamber 312 located on both sides of the first piston 32 and interconnected with each other. The second cylinder 41 has a second rodless chamber 411 and a second rod chamber 412 located on both sides of the second piston 42 and interconnected with each other. The first rodless chamber 311, the first rod chamber 312, the second rodless chamber 411, the second rod chamber 412 and the hydraulic pipe assembly 5 together form a closed oil circuit. When the first piston 32 and the second piston 42 are stationary, the oil pressure in the closed oil circuit reaches a balanced state.
[0032] Based on the above structural design, assuming the weight of the object to be weighed is G, the number of first hydraulic cylinders 3 is N, the number of second hydraulic cylinders 4 is M, and the oil pressure in the closed oil circuit of the weighing device is P.
[0033] Reference Figure 5 As shown, when the object to be weighed is placed on the weighing platform 1, the downward pressure exerted by the object on all the first pistons 32 is equal to its weight G. The hydraulic oil in the first rodless chamber 311 exerts an upward buoyancy force F1 = P × A1 on the first piston 32, and the hydraulic oil in the first rod chamber 312 exerts a downward pressure F2 = P × A2 on the first piston 32. Here, A1 is the effective working area of the first piston 32 on the first rodless chamber 311 side, and A2 is the effective working area of the first piston 32 on the first rod chamber 312 side.
[0034] It should be noted that the aforementioned effective working area refers to the area on which the hydraulic oil pressure actually acts on the first piston 32, and this working area is perpendicular to the direction of hydraulic oil pressure. For example, on the first rodless chamber 311 side, the hydraulic oil pressure can essentially act on the entire bottom surface of the first piston 32; therefore, the effective working area of the first piston 32 on the first rodless chamber 311 side is essentially equal to the bottom surface area of the first piston 32. As another example, on the first rod chamber 312 side, the top surface of the first piston 32 is approximately an annular surface, and the effective working area of the first piston 32 on the first rod chamber 312 side is essentially equal to the area of this annular surface. For the relatively regularly shaped first piston 32 and first piston rod 33, the area of this annular surface is theoretically equal to the difference between the bottom surface area of the first piston 32 and the cross-sectional area of the first piston rod 33.
[0035] When the first piston 32 remains stationary, it reaches force equilibrium. At this point, we can know that G = N × (F1 - F2) = N × P × (A1 - A2) = N × P × △A1. Where △A1 is the difference in effective working area between the two sides of the first piston 32, that is, △A1 = A1 - A2.
[0036] Reference Figure 6 As shown, assuming the thrust exerted by the second piston rod 43 of all second hydraulic cylinders 4 on the counterweight sensor 2 is F, the force exerted by the hydraulic oil in the second rodless chamber 411 on the second piston 42 is F3 = P × A3, and the force exerted by the hydraulic oil in the second rod chamber 412 on the second piston 42 is F4 = P × A4. Where A3 is the effective working area of the second piston 42 on one side of the second rodless chamber 411, and A4 is the effective working area of the second piston 42 on one side of the second rod chamber 412. The calculation method for the effective working areas on both sides of the second piston 42 is the same as that for the effective working areas on both sides of the first piston 32, and will not be repeated here.
[0037] When the second piston 42 remains stationary, it reaches force equilibrium. At this point, we can know that F = M × (F3 - F4) = M × P × (A3 - A4) = M × P × △A2. Where △A2 is the difference in effective working area between the two sides of the second piston 42, that is, △A2 = A3 - A4.
[0038] Based on the above derivation, by simultaneously solving the two formulas G=N×P×△A1 and F=M×P×△A2, we can obtain... .
[0039] Therefore, in practical applications, the thrust F applied to the object by the second piston rod 43 is obtained by the weighing sensor 2, and the specific values of N, M, △A1 and △A2 are obtained by the design parameters of the first hydraulic cylinder 3 and the second hydraulic cylinder 4, so that the weight G of the object to be weighed can be calculated.
[0040] In one embodiment, it can be seen from the above derivation process that the maximum load capacity F of the weighing sensor 2 is... MAX With the maximum load capacity G of the weighing device MAX The following relationship exists:
[0041]
[0042] In practical applications, the maximum load capacity G of the weighing device is usually preferred. MAX Greater than the maximum load capacity F of the load cell 2 MAX This allows the weighing range of the weighing sensor 2 to be increased.
[0043] Therefore, when the leverage coefficient When N×△A1>M×△A2, it is possible to make G MAX >F MAX Increase the weighing range of weighing sensor 2.
[0044] In one embodiment, the first piston rod 33 includes a first body portion 331, which is connected to the first piston 32 and extends through the end of the first cylinder 31 to the outside of the first cylinder 31. The second piston rod 43 includes a second body portion 431, which is connected to the second piston 42 and extends through the end of the second cylinder 41 to the outside of the second cylinder 41.
[0045] According to the conventional design of hydraulic cylinders, the difference in effective working areas ΔA1 between the two sides of the first piston 32 is generally equal to the cross-sectional area S1 of the first main body 331, i.e., ΔA1 = S1. Similarly, the difference in effective working areas ΔA2 between the two sides of the second piston 42 is generally equal to the cross-sectional area S2 of the second main body 431, i.e., ΔA2 = S2. To make the leverage coefficient Then it should make .
[0046] Furthermore, when the first main body portion 331 and the second main body portion 431 are configured as relatively regular circular rod structures, the cross-sectional area of the first main body portion 331 and the second main body portion 431 depends on their diameter. To make the leverage coefficient , should make That is, N×(D1) 2 >M×(D2) 2 Where D1 is the diameter of the first main body 331 and D2 is the diameter of the second main body 431.
[0047] Furthermore, considering the support strength, stability, and production cost of the weighing platform 1, a relatively large number of first hydraulic cylinders 3 and a relatively small number of second hydraulic cylinders 4 and load cells 2 are generally provided. Specifically, two or more first hydraulic cylinders 3, one second hydraulic cylinder 4, and one load cell 2 can be provided, i.e., N≥2, M=1. The formula for calculating the relationship between the weight G of the object to be weighed and the thrust F borne by the load cell 2 is as follows: .
[0048] Preferably, considering that the weighing platform 1 is mostly square, the first hydraulic cylinder 3 can be set to 4 and distributed at the four corners of the weighing platform 1.
[0049] Preferably, the diameter of the first main body 331 is set to be relatively large, and the diameter of the second main body 431 is set to be relatively large, i.e., D1 > D2, which can further reduce the leverage coefficient. The value further expands the maximum load capacity G of the weighing device. MAX .
[0050] In one embodiment, Figure 4 The diagram shows the state of the first hydraulic cylinder 3 when the object to be weighed is not placed on the weighing platform 1. As can be seen from the diagram, the hydraulic oil in the first rodless chamber 311 at the bottom of the first piston 32 exerts a relatively large upward buoyancy force on the first piston 32, causing the top surface of the first piston 32 to almost contact the top inner wall of the first cylinder body 31. There is almost no oil storage space at the top of the first piston 32, and the volume of the first rod chamber 312 is approximately zero. However, this does not affect the normal use of the weighing device. (Refer to...) Figure 5 As shown, once the object to be weighed is not placed on the weighing platform 1, the first piston 32 will move downward, forming a first rodless cavity 311 at its bottom and a first rod cavity 312 at its top.
[0051] In other embodiments, when the object to be weighed is not placed on the weighing platform 1, the top surface of the first piston 32 may also have a gap with the top inner wall of the first cylinder 31 to form a first rod cavity 312 with a certain volume.
[0052] In one embodiment, reference is made to Figure 4 and Figure 5 As shown, in order to facilitate the connection between the first rodless chamber 311 and the first rod chamber 312, and to maintain the oil pressure balance in various regions within the first cylinder 31, the first piston 32 is provided with an axially penetrating first oil passage 321. Similarly, referring to... Figure 6 As shown, the second piston 42 is provided with an axially penetrating second oil passage 421 to connect the second rodless chamber 411 and the second rod chamber 412.
[0053] It should be noted that the first oil passage 321 and the second oil passage 421 in the above embodiments are only one of the options available in practical applications. In other embodiments, it is also possible to connect the first rodless cavity 311 and the first rod cavity 312, as well as the second rodless cavity 411 and the second rod cavity 412, using external pipelines.
[0054] In one embodiment, reference is made to Figure 4 and Figure 5 As shown, a first connecting seat 7 is provided on the bottom frame 6, and the bottom of the first cylinder 31 is inserted into the first connecting seat 7. The bottom surface of the first cylinder 31 is spherical. A second connecting seat 8 is provided on the bottom of the weighing platform 1, and the top of the first piston rod 33 is inserted into the second connecting seat 8. The top surface of the first piston rod 33 is spherical. When the weighing platform 1 tilts slightly, the spherical surfaces at the ends of the first cylinder 31 and the first piston rod 33 can rotate slightly within the first connecting seat 7 and the second connecting seat 8, automatically adjusting to a new equilibrium position. This ensures that the force always passes perpendicularly through the central axis of the first piston rod 33, eliminating the influence of lateral forces and bending moments, and improving the weighing accuracy of the weighing device.
[0055] In one embodiment, reference is made to Figures 1 to 3 As shown, the weighing sensor 2, the second hydraulic cylinder 4, and the hydraulic pipe assembly 5 are all located below the weighing platform 1, with the weighing sensor 2 and the second hydraulic cylinder 4 specifically located on the bottom frame 6.
[0056] Furthermore, referring to Figure 6 As shown, the second hydraulic cylinder 4 extends approximately horizontally and is positioned opposite the load cell 2 in the same horizontal direction. The pressure-bearing portion 21 of the load cell 2 is configured as a hole-like structure. A pressure-bearing member 9 is provided at one end of the second piston rod 43 near the pressure-bearing portion 21. The pressure-bearing member 9 is inserted into the pressure-bearing portion 21 and abuts against the bottom of the hole in the pressure-bearing portion 21, applying force to the pressure-bearing portion 21.
[0057] In traditional weighing devices, the pressure-bearing part of the load cell is generally oriented vertically, cooperating with the support structure such as the support column at the bottom of the weighing platform to support the platform. In this application, the pressure-bearing part 21 of the load cell 2 is oriented approximately horizontally and is connected to the second hydraulic cylinder 4, which is also oriented approximately horizontally. The two abut against each other, and the load cell 2 detects the thrust applied to it by the second hydraulic cylinder 4.
[0058] It should be noted that in practical applications, considering limitations in manufacturing and installation precision, the orientation of the pressure-bearing part 21 is not necessarily strictly parallel to the horizontal direction, and a reasonable angular error is permissible. Further, refer to... Figure 6As shown, the load cell 2 is fixed on the first support 61, and the side of the second hydraulic cylinder 4 away from the load cell 2 is connected to the pivot shaft 63 of the second support 62. The pivot shaft 63 is perpendicular to the extension direction of the second hydraulic cylinder 4. When installing the second hydraulic cylinder 4 and the load cell 2, the second hydraulic cylinder 4 can rotate slightly around the pivot shaft 63 to adjust the angle of the second piston rod 43, so that the second piston rod 43 and the pressure bearing member 9 are aligned with the pressure bearing part 21 of the load cell 2, thereby improving the weighing accuracy of the weighing device.
[0059] In one embodiment, reference is made to Figure 2 As shown, the hydraulic pipe assembly 5 includes a first interface 53 and a second interface 54. The number of first interfaces 53 is the same as the number of first cylinders 31, and they are connected to all the first cylinders 31 in a one-to-one correspondence. The number of second interfaces 54 is the same as the number of second cylinders 41, and they are connected to all the second cylinders 41 in a one-to-one correspondence.
[0060] During the weighing process, regardless of where the object to be weighed is placed on the weighing platform 1, the hydraulic oil in the first cylinder 31, the second cylinder 41, and the hydraulic pipe assembly 5 can move freely, so that the oil pressure in each area of the closed oil circuit remains balanced, thus achieving accurate weighing by the weighing device. Therefore, the weighing device in this application does not limit the weighing position and there is no angle difference.
[0061] Furthermore, the hydraulic pipe assembly 5 includes multiple pipes 51, which are made of rigid metal material to prevent deformation of the pipes 51 and compression of the internal hydraulic oil. Two interconnected pipes 51 are connected by a hydraulic joint 52. The hydraulic joint 52 releases the internal stress caused by the asynchronous swinging of the two adjacent first hydraulic cylinders 3 during loading, preventing damage to the pipes 51 or the interfaces due to torsional forces.
[0062] Furthermore, in order to make the flow direction of the hydraulic oil approximately the same as the force transmission direction in the first hydraulic cylinder 3 and the second hydraulic cylinder 4, the first interface 53 of the hydraulic pipe assembly 5 is connected to the first rodless cavity 311 in the first cylinder 31, and the second interface 54 of the hydraulic pipe assembly 5 is connected to the second rodless cavity 411 in the second cylinder 41.
[0063] It should be noted that, in the process of deriving the formula for calculating the weight of the object to be weighed, this application does not consider the influence of the weights of the weighing platform 1, the first piston 32, and the first piston rod 33 on the weighing result for ease of understanding. Those skilled in the art can eliminate the influence of the weights on the weighing result by means of zero-point calibration, etc., and these means are easily known to those skilled in the art, and will not be elaborated in this application.
[0064] It will be apparent to those skilled in the art that this disclosure is not limited to the details of the exemplary embodiments described above, and that this disclosure can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of this disclosure is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this disclosure. No reference numerals in the claims should be construed as limiting the scope of the claims.
[0065] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
Claims
1. A weighing device, characterized in that, include: Weighing platform (1), used to support the object to be weighed; The weighing sensor (2) is located below the weighing platform (1), and the weighing sensor (2) includes a pressure-bearing part (21) that is generally oriented horizontally. The first hydraulic cylinder (3) includes a first cylinder body (31), a first piston (32) and a first piston rod (33), the first piston rod (33) supporting the weighing platform (1) from the bottom of the weighing platform (1); The second hydraulic cylinder (4) includes a second cylinder body (41), a second piston (42), and a second piston rod (43). The second cylinder body (41) is connected to the first cylinder body (31) and the internal oil pressure is equal. The pressure-bearing part (21) is arranged opposite to the second piston rod (43) to detect the force exerted by the second piston rod (43) against it.
2. The weighing device according to claim 1, characterized in that, The first hydraulic cylinder (3) and the second hydraulic cylinder (4) are configured to satisfy: N×△A1>M×△A2; Wherein, N is the number of the first hydraulic cylinders (3), △A1 is the difference in effective working area between the two sides of the first piston (32), M is the number of the second hydraulic cylinders (4), and △A2 is the difference in effective working area between the two sides of the second piston (42).
3. The weighing device according to claim 2, characterized in that, The first piston rod (33) includes a first main body portion (331) extending through the end of the first cylinder (31), and the second piston rod (43) includes a second main body portion (431) extending through the end of the second cylinder (41). The first hydraulic cylinder (3) and the second hydraulic cylinder (4) are configured to satisfy: △A1=S1, △A2=S2; Wherein, S1 is the area of the cross-section of the first main body (331), and S2 is the area of the cross-section of the second main body (431).
4. The weighing device according to claim 3, characterized in that, The first main body (331) and the second main body (431) are cylindrical rod structures, and the first hydraulic cylinder (3) and the second hydraulic cylinder (4) are configured to satisfy: N×(D1) 2 >M×(D2) 2 ; Wherein, D1 is the diameter of the first main body (331), and D2 is the diameter of the second main body (431).
5. The weighing device according to claim 4, characterized in that, The first hydraulic cylinder (3) and the second hydraulic cylinder (4) are configured to satisfy: D1>D2, N≥2, M=1.
6. The weighing device according to claim 1, characterized in that, The first piston (32) is provided with an axially penetrating first oil passage (321), and the second piston (42) is provided with an axially penetrating second oil passage (421).
7. The weighing device according to claim 1, characterized in that, The weighing device also includes a hydraulic pipe assembly (5) connected to the first cylinder (31) and the second cylinder (41). The hydraulic pipe assembly (5) includes a plurality of pipes (51), and two connected pipes (51) are connected by a hydraulic joint (52).
8. The weighing device according to claim 7, characterized in that, At least two first hydraulic cylinders (3) are provided, and the hydraulic pipe assembly (5) is connected to all of the first cylinder bodies (31).
9. The weighing device according to claim 1, characterized in that, The second hydraulic cylinder (4) extends horizontally and is positioned opposite the weighing sensor (2) in the horizontal direction.
10. The weighing device according to claim 1, characterized in that, The pressure-bearing part (21) is configured with a hole-like structure, and the second piston rod (43) has a pressure-bearing member (9) inserted into the pressure-bearing part (21) at one end near the pressure-bearing part (21).