WEIGH MODULE

Aweigh module with a load-receiving portion, a fixing portion, and a parallel guide portion also has a lever system with a first lever and a second lever. An additional portion of the load-receiving portion extends towards the fixing portion. An extension of the fixing portion extends towards the load-receiving portion. A first end of the first lever is connected by joints to the additional portion and the extension portion. A first end of the second lever is connected by joints to the second end of the first lever and to the extension portion. All joints are of a thin sheet structure. The second end of the second lever is configured for connection to a magnetic system. The weigh module is manufactured integrally. The use of the structure according to the present invention can meet design requirements of large range and small size of sensors.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a non-provisional application that claims priority to Chinese application 201911412205.X, filed 31 Dec. 2019.

TECHNICAL FIELD

The present invention relates to a weigh module, and in particular to a weigh module with the principle of electromagnetic force compensation.

BACKGROUND ART

At present, electromagnetic force compensation type weigh modules commonly used in electronic balances have different requirements in structure and range according to different service conditions. The working principle of the electromagnetic force compensation type weigh modules is based on the lever principle, and uses a small electromagnetic force to balance a relatively large loading force. For some weigh modules with a simple structure and a low range, a single lever structure can meet the weighing requirements. However, for weigh modules with a large capacity and a small size, the single lever structure often cannot meet the requirements, so it is necessary to use the form of two or more levers to achieve a larger lever ratio. The two-stage lever structure in the existing weigh module technology often uses a separated die-casting structure, and several major components on the weigh module, such as the load-receiving portion, a parallel guide portion, a fixing portion, and a lever, are respectively formed by die-casting and then connected together by means of screws, etc. The whole weigh module has a complex structure and numerous parts, and is time-consuming in assembly and high in cost.

SUMMARY

The technical problem to be solved by the present invention is to provide a weigh module to solve the problem in the prior art that a weigh module has a complex structure and numerous parts and is time-consuming in assembly and high in cost.

The present invention solves the above technical problem through the following technical solution:

providing a weigh module, comprising a load-receiving portion, a fixing portion, a parallel guide portion for connecting the load-receiving portion and the fixing portion, and a lever system, characterized in that the lever system is arranged in a space defined by the load-receiving portion, the fixing portion and the parallel guide portion and forms a gap from the load-receiving portion, the fixing portion and the parallel guide portion, and the lever comprises a first lever and a second lever;

the load-receiving portion extends towards the fixing portion to form a load-receiving portion additional portion; the fixing portion extends towards the load-receiving portion to form a fixing portion extension portion; a gap is formed between the load-receiving portion additional portion and the fixing portion extension portion; a gap is also formed between the lever system and the load-receiving portion additional portion and the fixing portion extension portion;

one end of the first lever is respectively connected to the load-receiving portion additional portion and the fixing portion extension portion, with joints thereof being both of a thin sheet structure;

the other end of the first lever is connected to one end of the second lever, and the end of the second lever is further connected to the fixing portion extension portion, with joints thereof also being both of a thin sheet structure;

the other end of the second lever is configured to be connected to a magnetic system; and

the weigh module is integrally manufactured.

In this solution, with the gap formed between the load-receiving portion additional portion and the fixing portion extension portion, the load-receiving portion additional portion and the fixing portion extension portion are separated from each other, and the size of the gap in this solution varies according to the design requirements of the lever structure.

In this solution, the load-receiving portion additional portion and the fixing portion extension portion are located in the space defined by the load-receiving portion, the fixing portion, and the parallel guide portion so as to, combined with the lever structure design, implement the precise force transmission and amplification.

In this solution, the thin sheet structure is implemented by making the joint between the components into a thin sheet by means of cutting, etc., thereby implementing the function of a fulcrum or better force transmission.

With the design of this solution, a force loaded by the load-receiving portion is transmitted to the first lever, and the force is diminished for the first time by using the fulcrum formed by the first lever and the fixing portion extension portion and transmitted to the second lever through the connection with the second lever. Then the force is diminished again by using the fulcrum formed by the second lever and the fixing portion extension portion and transmitted to the magnetic system, the two stages of levels are kept in a balanced state based on the electromagnetic force balance principle, and then the force loaded by the load-receiving portion is precisely measured through the proportional relationship between the force generated by the magnetic system and the lever.

In this solution, the load-receiving portion, the fixing portion, the parallel guide portion for connecting the load-receiving portion and the fixing portion, and the lever are integrally formed by means of integrated machining technology. Thus, the design of the overall structure of the sensor is more compact and is space-saving. Moreover, the integral forming design needs few types and a small number of parts, so the costs of machining, assembly, logistics, etc. are also lower.

Further, the fixing portion is provided with an opening, a slot or a through hole, and the second lever extends from one side to the other side of the fixing portion through the opening, the slot or the through hole.

In this solution, the second lever is designed to extend to the outer side of the fixing portion, thereby facilitating the assembly of the lever and the magnetic system.

Still further, one side of the fixing portion away from the load-receiving portion is provided with a magnetic system mounting portion.

Further, the other end of the second lever is connected to a coil connection portion, which is placed in the magnetic system.

In this solution, one end of the second lever is connected to the coil connection portion mounted in the magnetic system, such that the force generated by the magnetic system is transmitted to the second lever through the coil connection portion mounted with a coil, so as to keep the force balance between the first lever and the second lever.

Still further, the second lever and the coil connection portion are integrally formed.

In this solution, the second lever and the coil connection portion are integrally formed, thereby reducing the number of mounted parts. Moreover, the structure of the magnetic system is also simplified.

Further, the thin sheet structure is provided with at least one open slot from one side of the joint facing the load-receiving portion, or is provided with at least one open slot from one side of the joint facing the fixing portion, or is provided with at least one open slot from both sides of the joint facing the load-receiving portion and the fixing portion.

Further, the length from the joint between the first lever and the load-receiving portion additional portion to the joint between the first lever and the fixing portion extension portion is less than the length from the joint between the first lever and the second lever to the joint between the first lever and the fixing portion extension portion; and/or the length from the joint between the first lever and the second lever to the joint between the second lever and the fixing portion extension portion is less than the length from the gravity center of the magnetic system connected to the second lever to the joint between the second lever and the fixing portion extension portion.

In this solution, the total lever ratio of the two stages of levers is increased by means of adjusting the ratio of the levers at two sides of the fulcrums.

The positive improvement effect of the present invention is as follows: with the weigh module structure according to the present invention, a weigh module with a smaller size and a larger lever ratio can be obtained, and an integrated computer numerical control (CNC) machining form is used, such that the overall structure of the sensor is more compact and space-saving, and the types of parts are effectively reduced, thereby reducing costs of design, machining, assembly, logistics, etc.

The use of the structure according to the present invention can meet design requirements of large range and small size of sensors.

DETAILED DESCRIPTION OF EMBODIMENTS

The present invention will be further described below by way of examples, but the present invention is not therefore limited to the scope of the described embodiments.

According to the present invention, an integrated CNC machining form is used to effectively reduce the types of parts, thereby reducing the costs of design, machining, assembly, logistics, etc. Moreover, the connection and fulcrum functions of conventional flexure hinges are implemented through the connection between components in the weigh module by means of cutting, thereby avoiding the performance difference and unreliability caused by assembly.

Hereinafter, the implementation of the present invention will be illustrated by way of example via the following embodiments.

With regard to embodiments shown inFIGS. 1 and 2, a weigh module1of this embodiment comprises a load-receiving portion11, a fixing portion12, a parallel guide portion for connecting the load-receiving portion11to the fixing portion12, and a lever system14.

The parallel guide portion connects the fixing portion12and the load-receiving portion11together. The parallel guide portion comprises an upper parallel guide unit131and a lower parallel guide unit132parallel to each other, with two ends of the upper parallel guide unit131and the lower parallel guide unit132being respectively connected to the load-receiving portion11and the fixing portion12. The ends of the upper parallel guide unit131connected to the load-receiving portion11and the fixing portion12are cut into a thin sheet structure, and the function of the thin sheet structure is the same as that of a connecting flexure hinge in a weigh module assembled in the prior art, which will not be repeated here. In this embodiment, by means of cutting into the sheet structure, the weigh module is formed as an integrated structure by machining or by die-casting combined with machining. In this embodiment, the ends of the lower parallel guide unit132connected to the load-receiving portion11and the fixing portion12are also cut into a sheet structure. In this embodiment, the parallel guide portion, the fixing portion12and the load-receiving portion11form an integrated structure.

In this embodiment, two ends of the upper parallel guide unit131and the lower parallel guide unit132connected to the load-receiving portion11and the fixing portion12respectively have the same cross-sectional length. For example, the upper parallel guide unit131and the lower parallel guide unit132form a rectangle-like shape between the load-receiving portion11and the fixing portion12. In another embodiment, the upper parallel guide unit131and the lower parallel guide unit132forming a rectangle-like shape are each further provided with openings or open holes. In another variant embodiment, the number and shape of the openings or open holes in the upper parallel guide unit131and the lower parallel guide unit132can be adjusted arbitrarily.

In a further embodiment, when the two ends of the upper parallel guide unit131respectively connected to the load-receiving portion11and the fixing portion12have different cross-sectional lengths, in a direction from the end connected to the load-receiving portion11to the end connected to the fixing portion12, the distance between two sides of the upper parallel guide unit131gradually converts from the cross-sectional length of the end connected to the load-receiving portion to the cross-sectional length of the end connected to the fixing portion. In a variant embodiment, the lower parallel guide unit132and the upper parallel guide unit131have the same shape.

In this embodiment, one end of a load-receiving portion main body portion111of the load-receiving portion11connected to the lower parallel guide unit132extends towards the fixing portion12along the lower parallel guide unit132to form a load-receiving portion additional portion112. As shown inFIGS. 1 and 2, in this embodiment, the load-receiving portion additional portion112is located in a groove formed in a plane where the lower parallel guide unit132is located, so the cross-sectional area of the load-receiving portion additional portion112is smaller than that of the load-receiving portion main body portion111. The load-receiving portion additional portion112is connected to one end of the lever14close to the load-receiving portion11via a connecting portion. The connecting portion connected to the lever14is also cut into a thin sheet structure, and the cut thin sheet portion implements the function of a connecting flexure hinge between the load-receiving portion additional portion112and the lever14.

In this embodiment, a plurality of grooves are formed by cutting in the connecting portion to adjust the stress on the connecting portion, and those person skilled in the art would have been able to adjust the number, position, and size of the grooves according to the actual stress distribution on the connecting portion. For example, in another embodiment, the connecting portion is provided, at one side thereof facing the load-receiving portion11, with 2-3 grooves of the same size uniformly distributed in the lengthwise direction of the connecting portion so as to adjust the stress on the connecting portion.

In addition, the joints between the components are each cut into a sheet based on the existing machining process and requirements of weigh modules.

A fixing portion body portion121of the fixing portion12extends outwards in the lengthwise direction of the parallel guide portion for mounting a mounting portion124of a magnetic system. Upper and lower sides of the joint between the fixing portion body portion121and the mounting portion124are respectively provided with a first groove122and a second groove (not visible in the figure).

The fixing portion body portion121of the fixing portion12also extends towards the load-receiving portion11in a lengthwise direction of the parallel guide portion to form a first extension portion125. The first extension portion125of the fixing portion12further extends towards the lever14and the load-receiving portion11to form a second extension portion126. The first extension portion125and the second extension portion126of the fixing portion12are located between the upper parallel guide unit131and the lower parallel guide unit132which the parallel guide units are separated from each other. The second extension portion126and the load-receiving portion11are separated from each other so as to form a gap between the second extension portion126and the load-receiving portion11.

A spatial distance formed between the upper parallel guide unit131and the first extension portion125and the second extension portion126of the fixing portion12is large enough, as shown inFIGS. 1 and 2, such that the lever14can be placed in a space formed by the combination of the fixing portion body portion121, the upper parallel guide unit131, and the first extension portion125and the second extension portion126of the fixing portion12. In this embodiment, with such an arrangement structure, the weigh module has a compact structure and small size, is easy in machining and mounting, and has better performance.

In this embodiment, the lever14has a two-stage lever structure, the lever14and the load-receiving portion additional portion112are connected to one end1412of a body portion of a first lever141, the joint between the load-receiving portion additional portion112and the end1412is cut into a thin sheet structure, and the cut sheet portion implements the function of a connecting flexure hinge between the load-receiving portion additional portion112and the first lever141of the lever14.

The other end1413of the first lever141is connected to an end1422of a second lever142via a connecting portion, the connecting portion is cut into a thin sheet structure, and the cut thin sheet portion implements the function of a connecting flexure hinge between the first lever141and the second lever.

The first lever141is also connected to the second extension portion126of the fixing portion12via the end1412. The joint between the end1412and the second extension portion126is cut into a thin sheet structure, and the function of the thin sheet structure is the same as that of a fulcrum flexure hinge in a weigh module assembled in the prior art, which will not be repeated here. That is to say, the cut sheet structure implements the function of a fulcrum of the first lever141on the second extension portion126, such that the force loaded by the load-receiving portion11is diminished through the lever action of the joint between the end1412having the fulcrum function and the second extension portion126and is then transmitted to the second lever142.

A gap is formed between the second extension portion126and a connecting portion between the load-receiving portion additional portion112and the first lever, so a gap is also formed between the joint between the end1412and the second extension portion126and the joint between the load-receiving portion additional portion112and the end1412.

The end1422of the first lever142is also connected to the second extension portion126of the fixing portion12. The joint between the end1422and the second extension portion126is cut into a sheet structure, and the cut sheet structure implements the function of a fulcrum of the second lever142on the second extension portion126. Therefore, the force transmitted by the first lever is diminished through the lever having the fulcrum function, between the end1422and the second extension portion126and is then transmitted to the other end1423of the second lever142. Then the electromagnetic force received at the other end1423of the second lever142is calculated based on the electromagnetic force balance principle, and further the force actually loaded on the load-receiving portion11is obtained based on the amplification ratio of lever.

A gap is formed between the end1422and the second extension portion126and the joint between the end1413of the first lever141and the end1422of the second lever142. The joint between the end1422and the second extension portion126is closer to the load-receiving portion11than the joint between the end1413of the first lever141and the end1422of the second lever142.

That is to say, the lever ratio of the first lever is formed by the length from the joint between the first lever and the load-receiving portion additional portion to the joint between the first lever and the fixing portion extension portion and the length from the joint between the first lever and the second lever to the joint between the first lever and the fixing portion extension portion; and the level ratio of the second lever is formed by the length from the joint between the first lever and the second lever to the joint between the second lever and the fixing portion extension portion and the length from the gravity center of the magnetic system connected with the second lever to the joint between the second lever and the fixing portion extension portion. Through the linkage of the two stages of levers, the total lever ratio of the lever14is the product of the lever ratio of the first lever and the lever ratio of the second lever, and thus a greater lever ratio is obtained.

The other end1423of the second lever142passes through the first groove122and is connected to the magnetic system located at the mounting portion124. With the two-stage level structure of this embodiment, the overall structure of the weigh module is more compact and space-saving.

In this embodiment, the connection and fulcrum between components are implemented by using the cutting way. That is to say, in this embodiment, the fixing portion12, the parallel guide portion, the load-receiving portion11and the lever14form an integrated structure. In the manufacturing process, by means of pre-machining at the position of the sheet, the number of parts in the weigh module is reduced, and the cost and assembly time are saved.

In particular, in this embodiment, the first lever141and the second lever142are integrally formed. Therefore, the lever structure is more compact, and the number of parts assembled is reduced. In another embodiment, as shown inFIG. 3, the second lever142and the coil connection portion143are connected at the end1423and are integrally formed. In this embodiment, compared with the foregoing embodiment, the lever and the coil connection portion are of an integrated structure, such that the lever structure is more compact, and the number of parts assembled is reduced.

Of course, the specific shape of the lever14is not limited in the foregoing embodiments, and those skilled in the art would have been able to arbitrarily adjust the shape and size of the lever14according to an actual shape of a lever accommodation space of the weigh module and the shape and size of the opening of the lever accommodation space.

The weigh module in the foregoing embodiments has an integrated structure, that is, the weigh module is formed of a whole piece of material by integral molding. The above integrated structure may be an integrated structure formed by die-casting, or may be an integrated structure formed by machining, or may be an integrated structure formed by die-casting combined with machining. According to the design of the foregoing embodiments, a greater lever ratio is obtained within a limited size range. Moreover, an integrated CNC machining method effectively reduces the types of parts, thereby reducing the costs of design, machining, assembly, logistics, etc.

Although specific implementations of the present invention have been described above, those skilled in the art should understand that these are merely examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art would have been able to make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all these changes and modifications fall within the scope of protection of the present invention.