Mechanical measuring instrument overrun protection mechanism with self-recovery function and debugging method thereof

Abstract

The invention discloses a mechanical measuring instrument overrun protection mechanism with a self-recovery function and a debugging method thereof, and relates to the technical field of mechanical measuring instruments. The over-limit protection mechanism comprises a fixed connecting part, a floating part, an elastic deformation part and an overload limiting part; the fixed connecting part and the floating part are connected with the elastic deformation part to form a quadrilateral structure, the floating part always moves parallel to the fixed connecting part when bearing a tested load force, and a gap is reserved between the overload limiting part and the floating part and is used for limiting overload displacement of the floating part; when the floating part is stressed and deformed to a limit position, the floating part is in contact with the overload limiting part to limit further displacement of the floating part, so that the force transmitted to the measuring instrument is not increased any more; and after the over-limit load is unloaded, the elastic deformation part automatically resets, so that the clearance between the floating part and the overload limiting part is recovered. According to the over-limit protection mechanism, elastic deformation without frictional resistance can be achieved on the premise that parallel deformation guiding is achieved, over-limit protection is achieved in cooperation with a fixed limiting mechanism, and normal work can be automatically recovered after over-limit force is unloaded.

Description

Technical Field

[0001] This invention relates to the field of mechanical measuring instrument technology, specifically to an over-limit protection mechanism for mechanical measuring instruments with self-recovery function and its debugging method. Background Technology

[0002] Mechanical components of mechanical measuring instruments such as electromagnetic force-balanced weight detectors, balances, mass comparators, and force sensors all have load-bearing limits. Excessive loads applied to the sensitive elements of the instrument can cause irreversible damage, affecting the instrument's metrological performance and, in severe cases, destroying the instrument. Therefore, each instrument has a normal operating load-bearing limit.

[0003] However, in the process of measuring some mechanical quantities, if the load being measured is subjected to impact or possible human error, the load may exceed the load-bearing limit of the measuring instrument.

[0004] Therefore, most mechanical measuring instruments have over-limit protection mechanisms to prevent the core weighing element from being subjected to forces exceeding its load-bearing limit. Over-limit protection mechanisms typically work by deforming an elastic body. When the load reaches its maximum limit, the load receiver contacts the fixed limiting mechanism in advance, restricting further displacement of the load receiver and ensuring that the force transmitted to the core weighing element through the elastic body remains within the allowable range. Known over-limit protection mechanisms are mostly helical springs combined with guide mechanisms. Due to the frictional force present in sliding or rolling friction guide mechanisms, the deformation of the elastic body in the over-limit protection mechanism is affected by this friction. In instruments requiring high-precision mechanical measurements, the changes in the over-limit protection value caused by these frictional forces directly affect the instrument's measurement range and accuracy. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0006] Therefore, in a first aspect, the present invention provides an over-limit protection mechanism for a mechanical measuring instrument with a self-recovering function, comprising:

[0007] Fixed connection part, used for fixed connection with the measuring part of the measuring instrument;

[0008] The floating part is used to bear the load force being measured;

[0009] The elastic deformation part includes a first elastic deformation unit and a second elastic deformation unit, the fixed connection part is connected with the floating part through the first elastic deformation unit and the second elastic deformation unit respectively, so that the fixed connection part, the floating part, the first elastic deformation unit and the second elastic deformation unit form a quadrilateral structure, and the floating part always moves in parallel with the fixed connection part when bearing the measured load force;

[0010] The overload limiting part is arranged in the moving direction of the floating part and leaves a gap with the floating part, and is used for limiting the overload displacement of the floating part.

[0011] When the floating part is deformed to the limit position under force, the floating part is in contact with the overload limiting part to limit the further displacement of the floating part, so that the force transmitted to the measuring instrument is no longer increased; after unloading the overload, the elastic deformation part automatically resets to restore the gap between the floating part and the overload limiting part.

[0012] Further, the first elastic deformation unit includes:

[0013] The first flexible hinge is connected with the fixed connection part.

[0014] The second flexible hinge is connected with the floating part.

[0015] The first fixed connecting rod is connected with the first flexible hinge and the second flexible hinge at two ends respectively.

[0016] Further, the second elastic deformation unit includes:

[0017] The third flexible hinge is connected with the fixed connection part.

[0018] The fourth flexible hinge is connected with the floating part.

[0019] The second fixed connecting rod is connected with the third flexible hinge and the fourth flexible hinge at two ends respectively.

[0020] Further, the deformation points of the first flexible hinge, the second flexible hinge, the third flexible hinge and the fourth flexible hinge form the vertices of the quadrilateral.

[0021] Further, the first elastic deformation unit is a first leaf spring, and the first leaf spring is connected with the fixed connection part and the floating part respectively; the second elastic deformation unit is a second leaf spring, and the second leaf spring is connected with the fixed connection part and the floating part respectively.

[0022] Further, the over-limit protection mechanism further comprises an overload limiting part, which is arranged in the moving direction of the floating part and reserves a gap with the floating part, and is used for limiting the overload displacement of the floating part.

[0023] Further, the over-limit protection mechanism further comprises a damping device, which is arranged between the fixed connecting part and the floating part, and is used for inhibiting the moving vibration of the floating part.

[0024] In the second aspect, the application provides a debugging method of the over-limit protection mechanism, which comprises the following steps:

[0025] The adjustment method of the gap reserved between the overload limiting part and the floating part comprises the following steps: loading a critical overload load, adjusting the overload limiting part until it contacts the floating part, and taking the first change of the value shown by the measuring instrument as the contact determination basis.

[0026] Further, the debugging method further comprises the following steps:

[0027] The adjustment method of the gap reserved between the overload limiting part and the floating part comprises the following steps: loading a critical overload load, adjusting the overload limiting part until it contacts the floating part, and taking the first change of the value shown by the measuring instrument as the contact determination basis.

[0028] Compared with the prior art, the application has at least the following beneficial effects:

[0029] The over-limit protection mechanism of the mechanical measuring instrument with self-recovery function provided by the application is a guiding elastic deformation mechanism based on the quadrilateral double-side parallel principle, which can realize elastic deformation without frictional resistance on the premise of parallel deformation guiding, realizes over-limit protection in cooperation with the fixed limiting mechanism, and can automatically recover to normal work after unloading the over-limit force. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can also be obtained by those skilled in the art according to these drawings.

[0031] Figure 1 A schematic diagram of the overall structure of the over-limit protection mechanism of the mechanical measuring instrument with self-recovery function provided by the application; wherein, 1, fixed connecting part; 2, floating part; 3, elastic deformation part; 311, first flexible hinge; 312, second flexible hinge; 313, third flexible hinge; 314, fourth flexible hinge; 321, first fixed connecting rod; 322, second fixed connecting rod; 331, first leaf spring; 332, second leaf spring; 4, overload limiting part; 5, measuring instrument; 6, overload limiting part; 7, damping device.

[0032] Figure 2a The structure schematic diagram of the elastic deformation part of the over-limit protection mechanism of the mechanical measuring instrument with self-recovery function provided by the embodiment of the present application is a flexible hinge-fixed connecting rod.

[0033] Figure 2b The structure schematic diagram of the elastic deformation part of the over-limit protection mechanism of the mechanical measuring instrument with self-recovery function provided by the embodiment of the present application is a leaf spring. DETAILED DESCRIPTION

[0034] In order to better understand the above technical solutions, the technical solutions of the embodiments of the present application will be described in detail below through the drawings and specific embodiments. It should be understood that the specific features in the embodiments of the present application and the specific features in the embodiments are detailed descriptions of the technical solutions of the embodiments of the present application, and are not limitations of the technical solutions of the present application. In the case of no conflict, the technical features in the embodiments of the present application and the embodiments can be combined with each other.

[0035] In the first aspect of the embodiment of the present application, referring to Figure 1 , an over-limit protection mechanism of a mechanical measuring instrument with self-recovery function is provided, comprising:

[0036] A fixed connecting part 1 is used for fixed connection with a measuring part of a measuring instrument 5;

[0037] A floating part 2 is used for bearing a measured load force;

[0038] An elastic deformation part 3 includes a first elastic deformation unit and a second elastic deformation unit, and the fixed connecting part 1 is connected with the floating part 2 through the first elastic deformation unit and the second elastic deformation unit, respectively, so as to form a quadrilateral structure of the fixed connecting part 1, the floating part 2, the first elastic deformation unit and the second elastic deformation unit, and the floating part 2 always keeps parallel movement with the fixed connecting part 1 when bearing the measured load force;

[0039] An overload limiting part 4 is provided in the moving direction of the floating part 2 and leaves a gap with the floating part 2, and is used for limiting the overload displacement of the floating part 2;

[0040] When the floating part 2 is deformed to the limit position under force, the floating part 2 contacts the overload limiting part 4 to limit the further displacement of the floating part 2, so that the force transmitted to the measuring instrument 5 is no longer increased; after unloading the over-limit load, the elastic deformation part 3 automatically resets to restore the gap between the floating part 2 and the overload limiting part 4.

[0041] The over-limit protection mechanism of the mechanical measuring instrument with self-recovery function provided by the embodiment of the application is a guiding elastic deformation mechanism based on the parallelogram double-side parallel principle, which can realize elastic deformation without friction resistance on the premise of parallel deformation guiding, realizes over-limit protection in cooperation with the fixed limiting mechanism, and can automatically recover to normal work after unloading the over-limit force.

[0042] Specifically, the fixed connection part 1 and the floating part 2 are two parallel opposite sides of a parallelogram, the first elastic deformation unit and the second elastic deformation unit are the other two parallel opposite sides of the parallelogram, and the parallelogram guiding mechanism is formed. When the floating part 2 bears the measured load force, the fixed connection part 1 is fixed, the floating part 2 moves up and down due to the deformation of the elastic deformation part 3, and always maintains a parallel state with the fixed connection part 1. The overload limiting part 4 is arranged in the moving direction of the floating part 2 and is fixed on the base of the measuring instrument 5. In the normal measurement state, the overload limiting part 4 maintains a certain gap with the floating part 2, and when the floating part 2 is deformed to reach the limit position under force, the overload limiting part 4 is in contact with the floating part 2. The overload limiting part 4 provides a supporting force to limit the further deformation of the floating part 2. At this time, even if the external load force continues to increase, the deformation amount of the elastic deformation part 3 will no longer increase, and the force transmitted from the fixed connection part 1 to the measuring instrument 5 will also no longer increase, thereby playing a role in over-limit protection. When the over-limit load is unloaded, the elastic deformation part 3 will restore to the original state under the action of the elastic force, so that an air gap is formed between the floating part 2 and the overload limiting part 4, and the measuring instrument 5 can quickly recover to the normal measurement state. At the same time, since it is ensured that the load force borne by the measuring instrument 5 is always within a suitable working range, the stabilization time of the measuring instrument 5 after the measured load is loaded can be shortened.

[0043] In some embodiments, the elastic deformation part 3 is a flexible hinge-fixed link structure, as shown in Figure 2a .

[0044] The first elastic deformation unit comprises:

[0045] The first flexible hinge 311 is connected to the fixed connection part 1.

[0046] The second flexible hinge 312 is connected to the floating part 2.

[0047] The first fixed link 321 is connected to the first flexible hinge 311 and the second flexible hinge 312 at both ends.

[0048] The second elastic deformation unit comprises:

[0049] The third flexible hinge 313 is connected to the fixed connection part 1.

[0050] The fourth flexible hinge 314 is connected to the floating part 2.

[0051] The second fixed connecting rod 322 is connected with the third flexible hinge 313 and the fourth flexible hinge 314 respectively.

[0052] Specifically, when the flexible hinge-fixed connecting rod structure is adopted, the thinnest part of the flexible hinge is taken as the deformation point, and the deformation points of the first flexible hinge 311, the second flexible hinge 312, the third flexible hinge 313 and the fourth flexible hinge 314 form the vertices of the parallelogram, so that the floating part 2 can be moved along the direction parallel to the fixed connecting part 1 to the maximum extent.

[0053] In some embodiments, the elastic deformation part 3 is a leaf spring structure, as shown in the figure. The first elastic deformation unit is the first leaf spring 331, and the first leaf spring 331 is connected with the fixed connecting part 1 and the floating part 2 respectively. The second elastic deformation unit is the second leaf spring 332, and the second leaf spring 332 is connected with the fixed connecting part 1 and the floating part 2 respectively. Figure 2b

[0054] Specifically, when the leaf spring structure is adopted, the overall deformation of the leaf spring can maximize the elastic range of the leaf spring material, and can expand the deformation amount of the overrunning protection mechanism for small load conditions, thereby improving the applicability of the overrunning protection mechanism to small loads.

[0055] In some embodiments, the overrunning protection mechanism further comprises an underload limiting part 6 arranged in the moving direction of the floating part 2 and leaving a gap with the floating part 2, for limiting the underload displacement of the floating part 2.

[0056] It can be understood that in some measurement conditions, the automatic measurement range of the measuring instrument 5 is smaller than its maximum measurement range, and the measurement needs to rely on balancing to be realized. At this time, the measuring instrument 5 is a mantissa measuring instrument, and the measured force value is generally unloaded in full amount, not only the load amount within the automatic measurement range of the measuring instrument 5. At this time, the measuring instrument 5 and the overrunning protection mechanism will be in an underload overrunning condition. In order to limit both underload overrunning and overload overrunning, the underload limiting part 6 is further arranged in the measuring instrument 5 with underload overrunning, and the overload limiting part 4 and the underload limiting part 6 are arranged in the two moving directions of the floating part 2 respectively. When the overload is loaded, the further displacement of the floating part 2 is limited by the overload limiting part 4; when the underload is loaded, the further displacement of the floating part 2 is limited by the underload limiting part 6, so as to ensure that the load force transmitted to the measuring instrument 5 is always within the required normal range in the case of overload or underload. Such design changes the protection capability of the overrunning protection mechanism from one-way to two-way, which can effectively ensure that the protected measuring instrument 5 is always within the appropriate load loading range.

[0057] ​In some embodiments, the over-limit protection mechanism further comprises a damping device 7 arranged between the fixed connection part 1 and the floating part 2 for damping the movement vibration of the floating part 2.

[0058] Specifically, for the case that the elastic deformation part 3 is sensitive to the movement vibration of some measuring instrument 5, the damping device 6 is arranged between the fixed connection part 1 and the floating part 2, and when the load applied on the floating part 2 changes, the movement of the floating part 2 relative to the fixed connection part 1 will quickly reach a balanced state under the action of the damping device 6.

[0059] In the second aspect of the embodiments of the present application, a debugging method of the over-limit protection mechanism is provided, wherein the over-load limiting debugging method comprises: loading a critical over-load, adjusting the over-load limiting part 4 until it contacts with the floating part 2, and taking the first change of the value shown by the measuring instrument 5 as the contact judging basis. The under-load limiting debugging method comprises: loading a critical under-load, adjusting the under-load limiting part 6 until it contacts with the floating part 2, and taking the first change of the value shown by the measuring instrument 5 as the contact judging basis.

[0060] Specifically, the adjustment method of the gap between the over-load limiting part 4 and the floating part 2 is the over-load limiting debugging method, which is specifically: when adjusting the over-load, the load value is the critical value of the over-load, the over-load limiting part 4 is adjusted until it just contacts with the floating part 2, and the value shown by the measuring instrument 5 can be observed for auxiliary judgment, and when the value shown by the measuring instrument 5 just changes, it is the just contact position. The adjustment method of the gap between the under-load limiting part 6 and the floating part 2 is the under-load limiting debugging method, which is specifically: the load value is the critical value of the under-load, the under-load limiting part 6 is adjusted until it just contacts with the floating part 2, and the value shown by the measuring instrument 5 can be observed for auxiliary judgment, and when the value shown by the measuring instrument 5 just changes, it is the just contact position.

[0061] Further, since the purpose of the over-limit protection mechanism is to protect the measuring instrument 5 to always be within the working load range, and the measuring instrument 5 will not be affected by the over-limit protection mechanism when it is working normally, it is most reasonable and rapid to take the measured value of the measuring instrument 5 as the adjustment basis of the fixed limiting part 4.

[0062] It is easy for those skilled in the art to understand that the above advantageous modes can be freely combined and superimposed without conflict. The above is only the preferred embodiment of the present application and does not limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application. The above is only the preferred embodiment of the present application, and it should be pointed out that, for ordinary skilled in the art, without departing from the technical principles of the present application, a number of improvements and modifications can be made, and these improvements and modifications shall be regarded as the protection scope of the present application.

Claims

1. An over-limit protection mechanism for a mechanical measuring instrument with self-recovery function, characterized in that, include: Fixed connection part (1) is used for fixed connection with the measuring part of the measuring instrument (5); The floating part (2) is used to bear the load force being measured; The elastic deformation part (3) includes a first elastic deformation unit and a second elastic deformation unit. The fixed connection part (1) is connected to the floating part (2) through the first elastic deformation unit and the second elastic deformation unit respectively, so that the fixed connection part (1), the floating part (2), the first elastic deformation unit and the second elastic deformation unit form a quadrilateral structure, and the floating part (2) always moves parallel to the fixed connection part (1) when bearing the measured load force. An overload limiting part (4) is provided in the moving direction of the floating part (2) and has a reserved gap with the floating part (2) to limit the overload displacement of the floating part (2); When the floating part (2) is deformed to its limit position, the floating part (2) contacts the overload limiting part (4) to limit the further displacement of the floating part (2) so that the force transmitted to the measuring instrument (5) no longer increases; after unloading the overload, the elastic deformation part (3) automatically resets so that the gap between the floating part (2) and the overload limiting part (4) is restored.

2. The over-limit protection mechanism for mechanical measuring instruments with self-recovery function according to claim 1, characterized in that, The first elastic deformation unit includes: A first flexible hinge (311) is connected to the fixed connection part (1); A second flexible hinge (312) connects to the floating part (2); The first fixed link (321) is connected at both ends to the first flexible hinge (311) and the second flexible hinge (312); The second elastic deformation unit includes: A third flexible hinge (313) is connected to the fixed connection part (1); A fourth flexible hinge (314) connects the floating part (2); The second fixed link (322) is connected at both ends to the third flexible hinge (313) and the fourth flexible hinge (314).

3. The over-limit protection mechanism for mechanical measuring instruments with self-recovery function according to claim 2, characterized in that, The deformation points of the first flexible hinge (311), the second flexible hinge (312), the third flexible hinge (313), and the fourth flexible hinge (314) form the vertices of the quadrilateral.

4. The over-limit protection mechanism for mechanical measuring instruments with self-recovery function according to claim 1, characterized in that, The first elastic deformation unit is a first leaf spring (331), which is connected to the fixed connection part (1) and the floating part (2) respectively; the second elastic deformation unit is a second leaf spring (332), which is connected to the fixed connection part (1) and the floating part (2) respectively.

5. The over-limit protection mechanism for mechanical measuring instruments with self-recovery function according to claim 1, characterized in that, The overload protection mechanism also includes an underload limiting part (6), which is provided in the moving direction of the floating part (2) and has a reserved gap with the floating part (2) to limit the underload displacement of the floating part (2).

6. The over-limit protection mechanism for mechanical measuring instruments with self-recovery function according to claim 1, characterized in that, The over-limit protection mechanism also includes a damping device (7), which is disposed between the fixed connection part (1) and the floating part (2) to suppress the movement vibration of the floating part (2).

7. A method for debugging an over-limit protection mechanism, characterized in that, The debugging method of the over-limit protection mechanism according to any one of claims 1-5 includes: The method for adjusting the gap between the overload limiting part (4) and the floating part (2) is as follows: apply a critical overload load, adjust the overload limiting part (4) until it contacts the floating part (2), and use the first change in the value of the measuring instrument (5) as the basis for determining contact.

8. The debugging method for the over-limit protection mechanism according to claim 7, characterized in that, The debugging method also includes: The method for adjusting the gap between the underload limiting part (6) and the floating part (2) is as follows: apply a critical underload load, adjust the underload limiting part (6) until it contacts the floating part (2), and use the first change in the value of the measuring instrument (5) as the basis for determining contact.

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